1
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Nechaeva T, Verra L, Pucek J, Ranc L, Bergamaschi M, Zevi Della Porta G, Muggli P, Agnello R, Ahdida CC, Amoedo C, Andrebe Y, Apsimon O, Apsimon R, Arnesano JM, Bencini V, Blanchard P, Burrows PN, Buttenschön B, Caldwell A, Chung M, Cooke DA, Davut C, Demeter G, Dexter AC, Doebert S, Farmer J, Fasoli A, Fonseca R, Furno I, Granados E, Granetzny M, Graubner T, Grulke O, Gschwendtner E, Guran E, Henderson J, Kedves MÁ, Kim SY, Kraus F, Krupa M, Lefevre T, Liang L, Liu S, Lopes N, Lotov K, Martinez Calderon M, Mazzoni S, Moon K, Morales Guzmán PI, Moreira M, Okhotnikov N, Pakuza C, Pannell F, Pardons A, Pepitone K, Poimenidou E, Pukhov A, Rey S, Rossel R, Saberi H, Schmitz O, Senes E, Silva F, Silva L, Spear B, Stollberg C, Sublet A, Swain C, Topaloudis A, Torrado N, Turner M, Velotti F, Verzilov V, Vieira J, Welsch C, Wendt M, Wing M, Wolfenden J, Woolley B, Xia G, Yarygova V, Zepp M. Hosing of a Long Relativistic Particle Bunch in Plasma. Phys Rev Lett 2024; 132:075001. [PMID: 38427892 DOI: 10.1103/physrevlett.132.075001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/16/2024] [Indexed: 03/03/2024]
Abstract
Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, self-modulation in the perpendicular plane, at frequencies close to the plasma electron frequency, and are reproducible. Development of hosing depends on misalignment direction, its growth on misalignment extent and on proton bunch charge. Results have the main characteristics of a theoretical model, are relevant to other plasma-based accelerators and represent the first characterization of hosing.
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Affiliation(s)
- T Nechaeva
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - L Verra
- CERN, 1211 Geneva 23, Switzerland
| | - J Pucek
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - L Ranc
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - M Bergamaschi
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - G Zevi Della Porta
- Max Planck Institute for Physics, 80805 Munich, Germany
- CERN, 1211 Geneva 23, Switzerland
| | - P Muggli
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - R Agnello
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | | | - C Amoedo
- CERN, 1211 Geneva 23, Switzerland
| | - Y Andrebe
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - O Apsimon
- University of Manchester M13 9PL, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - R Apsimon
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- Lancaster University, Lancaster LA1 4YB, United Kingdom
| | | | - V Bencini
- CERN, 1211 Geneva 23, Switzerland
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | - P Blanchard
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - P N Burrows
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | - B Buttenschön
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Caldwell
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - M Chung
- UNIST, Ulsan 44919, Republic of Korea
| | | | - C Davut
- University of Manchester M13 9PL, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - G Demeter
- Wigner Research Centre for Physics, 1121 Budapest, Hungary
| | - A C Dexter
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- Lancaster University, Lancaster LA1 4YB, United Kingdom
| | | | - J Farmer
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - A Fasoli
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - R Fonseca
- ISCTE - Instituto Universitéario de Lisboa, 1049-001 Lisbon, Portugal
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - I Furno
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | | | - M Granetzny
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - T Graubner
- Philipps-Universität Marburg, 35032 Marburg, Germany
| | - O Grulke
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
- Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | | | - E Guran
- CERN, 1211 Geneva 23, Switzerland
| | - J Henderson
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- STFC/ASTeC, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - M Á Kedves
- Wigner Research Centre for Physics, 1121 Budapest, Hungary
| | - S-Y Kim
- CERN, 1211 Geneva 23, Switzerland
- UNIST, Ulsan 44919, Republic of Korea
| | - F Kraus
- Philipps-Universität Marburg, 35032 Marburg, Germany
| | - M Krupa
- CERN, 1211 Geneva 23, Switzerland
| | | | - L Liang
- University of Manchester M13 9PL, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - S Liu
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - N Lopes
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - K Lotov
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | | | | | - K Moon
- UNIST, Ulsan 44919, Republic of Korea
| | | | - M Moreira
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - N Okhotnikov
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - C Pakuza
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | | | | | - K Pepitone
- Angstrom Laboratory, Department of Physics and Astronomy, 752 37 Uppsala, Sweden
| | | | - A Pukhov
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
- Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - S Rey
- CERN, 1211 Geneva 23, Switzerland
| | - R Rossel
- CERN, 1211 Geneva 23, Switzerland
| | - H Saberi
- University of Manchester M13 9PL, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - O Schmitz
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - E Senes
- CERN, 1211 Geneva 23, Switzerland
| | - F Silva
- INESC-ID, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - L Silva
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - B Spear
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | - C Stollberg
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - A Sublet
- CERN, 1211 Geneva 23, Switzerland
| | - C Swain
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | | | - N Torrado
- CERN, 1211 Geneva 23, Switzerland
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - M Turner
- CERN, 1211 Geneva 23, Switzerland
| | | | - V Verzilov
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - J Vieira
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - C Welsch
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - M Wendt
- CERN, 1211 Geneva 23, Switzerland
| | - M Wing
- UCL, London WC1 6BT, United Kingdom
| | - J Wolfenden
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | | | - G Xia
- University of Manchester M13 9PL, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - V Yarygova
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - M Zepp
- University of Wisconsin, Madison, Wisconsin 53706, USA
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Tema Biwole A, Porte L, Coda S, Fasoli A. Vertical electron cyclotron emission diagnostic on the tokamak à configuration variable. Rev Sci Instrum 2023; 94:103504. [PMID: 37801369 DOI: 10.1063/5.0156000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 09/13/2023] [Indexed: 10/08/2023]
Abstract
In this paper, a diagnostic for the measurement of the electron cyclotron emission (ECE) from non-thermal electrons in magnetically confined fusion plasmas is presented. The diagnostic employs a vertical viewing line of sight that allows us to directly infer the energy of the emitting electrons. Previous incarnations of this diagnostic on other machines have been limited by refraction, which can cause stray radiation to enter the line of sight, polluting the signal. By tuning the toroidal magnetic field on the Tokamak à Configuration Variable, TCV, and by carefully selecting the range of frequencies that are used to measure the ECE spectrum, refraction can be mitigated and background radiation power reduced to below the noise power of the instrumentation. A novel technique for calibrating the diagnostic based on plasma measurements and modeling has been developed. The paper will describe the Vertical ECE (V-ECE) diagnostic on TCV, the calibration method, and the first results from the measurements.
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Biwole AT, Porte L, Coda S, Fasoli A. Publisher's Note: "Vertical electron cyclotron emission diagnostic on the tokamak à configuration variable" [Rev. Sci. Instrum. 94, 103504 (2023)]. Rev Sci Instrum 2023; 94:109901. [PMID: 37861405 DOI: 10.1063/5.0180915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Indexed: 10/21/2023]
Affiliation(s)
- A Tema Biwole
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - L Porte
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - S Coda
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
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Ambrogio S, Narayanan P, Okazaki A, Fasoli A, Mackin C, Hosokawa K, Nomura A, Yasuda T, Chen A, Friz A, Ishii M, Luquin J, Kohda Y, Saulnier N, Brew K, Choi S, Ok I, Philip T, Chan V, Silvestre C, Ahsan I, Narayanan V, Tsai H, Burr GW. An analog-AI chip for energy-efficient speech recognition and transcription. Nature 2023; 620:768-775. [PMID: 37612392 PMCID: PMC10447234 DOI: 10.1038/s41586-023-06337-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 06/16/2023] [Indexed: 08/25/2023]
Abstract
Models of artificial intelligence (AI) that have billions of parameters can achieve high accuracy across a range of tasks1,2, but they exacerbate the poor energy efficiency of conventional general-purpose processors, such as graphics processing units or central processing units. Analog in-memory computing (analog-AI)3-7 can provide better energy efficiency by performing matrix-vector multiplications in parallel on 'memory tiles'. However, analog-AI has yet to demonstrate software-equivalent (SWeq) accuracy on models that require many such tiles and efficient communication of neural-network activations between the tiles. Here we present an analog-AI chip that combines 35 million phase-change memory devices across 34 tiles, massively parallel inter-tile communication and analog, low-power peripheral circuitry that can achieve up to 12.4 tera-operations per second per watt (TOPS/W) chip-sustained performance. We demonstrate fully end-to-end SWeq accuracy for a small keyword-spotting network and near-SWeq accuracy on the much larger MLPerf8 recurrent neural-network transducer (RNNT), with more than 45 million weights mapped onto more than 140 million phase-change memory devices across five chips.
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Affiliation(s)
- S Ambrogio
- IBM Research - Almaden, San Jose, CA, USA.
| | | | - A Okazaki
- IBM Research - Tokyo, Kawasaki, Japan
| | - A Fasoli
- IBM Research - Almaden, San Jose, CA, USA
| | - C Mackin
- IBM Research - Almaden, San Jose, CA, USA
| | | | - A Nomura
- IBM Research - Tokyo, Kawasaki, Japan
| | - T Yasuda
- IBM Research - Tokyo, Kawasaki, Japan
| | - A Chen
- IBM Research - Almaden, San Jose, CA, USA
| | - A Friz
- IBM Research - Almaden, San Jose, CA, USA
| | - M Ishii
- IBM Research - Tokyo, Kawasaki, Japan
| | - J Luquin
- IBM Research - Almaden, San Jose, CA, USA
| | - Y Kohda
- IBM Research - Tokyo, Kawasaki, Japan
| | - N Saulnier
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - K Brew
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - S Choi
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - I Ok
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - T Philip
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - V Chan
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - C Silvestre
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - I Ahsan
- IBM Research - Albany NanoTech Center, Albany, NY, USA
| | - V Narayanan
- IBM Thomas J. Watson Research Center, Yorktown Heights, NY, USA
| | - H Tsai
- IBM Research - Almaden, San Jose, CA, USA
| | - G W Burr
- IBM Research - Almaden, San Jose, CA, USA
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Choi KM, Ko CY, An SM, Cho SH, Rowland DJ, Kim JH, Fasoli A, Chaudhari AJ, Bers DM, Yoon JC. Regulation of beige adipocyte thermogenesis by the cold-repressed ER protein NNAT. Mol Metab 2023; 69:101679. [PMID: 36708951 PMCID: PMC9932177 DOI: 10.1016/j.molmet.2023.101679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Cold stimuli trigger the conversion of white adipose tissue into beige adipose tissue, which is capable of non-shivering thermogenesis. However, what process drives this activation of thermogenesis in beige fat is not well understood. Here, we examine the ER protein NNAT as a regulator of thermogenesis in adipose tissue. METHODS We investigated the regulation of adipose tissue NNAT expression in response to changes in ambient temperature. We also evaluated the functional role of NNAT in thermogenic regulation using Nnat null mice and primary adipocytes that lack or overexpress NNAT. RESULTS Cold exposure or treatment with a β3-adrenergic agonist reduces the expression of adipose tissue NNAT in mice. Genetic disruption of Nnat in mice enhances inguinal adipose tissue thermogenesis. Nnat null mice exhibit improved cold tolerance both in the presence and absence of UCP1. Gain-of-function studies indicate that ectopic expression of Nnat abolishes adrenergic receptor-mediated respiration in beige adipocytes. NNAT physically interacts with the ER Ca2+-ATPase (SERCA) in adipocytes and inhibits its activity, impairing Ca2+ transport and heat dissipation. We further demonstrate that NHLRC1, an E3 ubiquitin protein ligase implicated in proteasomal degradation of NNAT, is induced by cold exposure or β3-adrenergic stimulation, thus providing regulatory control at the protein level. This serves to link cold stimuli to NNAT degradation in adipose tissue, which in turn leads to enhanced SERCA activity. CONCLUSIONS Our study implicates NNAT in the regulation of adipocyte thermogenesis.
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Affiliation(s)
- Kyung-Mi Choi
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA; Institute of Molecular Biology and Genetics, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Christopher Y Ko
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Sung-Min An
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Seung-Hee Cho
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Jung Hak Kim
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Anna Fasoli
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Abhijit J Chaudhari
- Department of Radiology, University of California Davis School of Medicine, Sacramento, CA 95825, USA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - John C Yoon
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA.
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Ogata G, Partida GJ, Fasoli A, Ishida AT. Calcium/calmodulin-dependent protein kinase II associates with the K + channel isoform Kv4.3 in adult rat optic nerve. Front Neuroanat 2022; 16:958986. [PMID: 36172564 PMCID: PMC9512010 DOI: 10.3389/fnana.2022.958986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/10/2022] [Indexed: 11/25/2022] Open
Abstract
Spikes are said to exhibit "memory" in that they can be altered by spikes that precede them. In retinal ganglion cell axons, for example, rapid spiking can slow the propagation of subsequent spikes. This increases inter-spike interval and, thus, low-pass filters instantaneous spike frequency. Similarly, a K+ ion channel blocker (4-aminopyridine, 4AP) increases the time-to-peak of compound action potentials recorded from optic nerve, and we recently found that reducing autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII) does too. These results would be expected if CaMKII modulates spike propagation by regulating 4AP-sensitive K+ channels. As steps toward identifying a possible substrate, we test whether (i) 4AP alters optic nerve spike shape in ways consistent with reducing K+ current, (ii) 4AP alters spike propagation consistent with effects of reducing CaMKII activation, (iii) antibodies directed against 4AP-sensitive and CaMKII-regulated K+ channels bind to optic nerve axons, and (iv) optic nerve CaMKII co-immunoprecipitates with 4AP-sensitive K+ channels. We find that, in adult rat optic nerve, (i) 4AP selectively slows spike repolarization, (ii) 4AP slows spike propagation, (iii) immunogen-blockable staining is achieved with anti-Kv4.3 antibodies but not with antibodies directed against Kv1.4 or Kv4.2, and (iv) CaMKII associates with Kv4.3. Kv4.3 may thus be a substrate that underlies activity-dependent spike regulation in adult visual system pathways.
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Affiliation(s)
- Genki Ogata
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
| | - Gloria J. Partida
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
| | - Anna Fasoli
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
| | - Andrew T. Ishida
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA, United States
- Department of Ophthalmology and Vision Science, University of California, Sacramento, Sacramento, CA, United States
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7
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Verra L, Zevi Della Porta G, Pucek J, Nechaeva T, Wyler S, Bergamaschi M, Senes E, Guran E, Moody JT, Kedves MÁ, Gschwendtner E, Muggli P, Agnello R, Ahdida CC, Goncalves MCA, Andrebe Y, Apsimon O, Apsimon R, Arnesano JM, Bachmann AM, Barrientos D, Batsch F, Bencini V, Blanchard P, Burrows PN, Buttenschön B, Caldwell A, Chappell J, Chevallay E, Chung M, Cooke DA, Davut C, Demeter G, Dexter AC, Doebert S, Elverson FA, Farmer J, Fasoli A, Fedosseev V, Fonseca R, Furno I, Gorn A, Granados E, Granetzny M, Graubner T, Grulke O, Hafych V, Henderson J, Hüther M, Khudiakov V, Kim SY, Kraus F, Krupa M, Lefevre T, Liang L, Liu S, Lopes N, Lotov K, Martinez Calderon M, Mazzoni S, Medina Godoy D, Moon K, Morales Guzmán PI, Moreira M, Nowak E, Pakuza C, Panuganti H, Pardons A, Pepitone K, Perera A, Pukhov A, Ramjiawan RL, Rey S, Schmitz O, Silva F, Silva L, Stollberg C, Sublet A, Swain C, Topaloudis A, Torrado N, Tuev P, Velotti F, Verzilov V, Vieira J, Weidl M, Welsch C, Wendt M, Wing M, Wolfenden J, Woolley B, Xia G, Yarygova V, Zepp M. Controlled Growth of the Self-Modulation of a Relativistic Proton Bunch in Plasma. Phys Rev Lett 2022; 129:024802. [PMID: 35867433 DOI: 10.1103/physrevlett.129.024802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
A long, narrow, relativistic charged particle bunch propagating in plasma is subject to the self-modulation (SM) instability. We show that SM of a proton bunch can be seeded by the wakefields driven by a preceding electron bunch. SM timing reproducibility and control are at the level of a small fraction of the modulation period. With this seeding method, we independently control the amplitude of the seed wakefields with the charge of the electron bunch and the growth rate of SM with the charge of the proton bunch. Seeding leads to larger growth of the wakefields than in the instability case.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - R Agnello
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | | | | | - Y Andrebe
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - O Apsimon
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - R Apsimon
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- Lancaster University, Lancaster LA1 4YB, United Kingdom
| | | | - A-M Bachmann
- Max Planck Institute for Physics, 80805 Munich, Germany
| | | | - F Batsch
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - V Bencini
- CERN, 1211 Geneva 23, Switzerland
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | - P Blanchard
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - P N Burrows
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | - B Buttenschön
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Caldwell
- Max Planck Institute for Physics, 80805 Munich, Germany
| | | | | | - M Chung
- UNIST, Ulsan 44919, Republic of Korea
| | | | - C Davut
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- University of Manchester, Manchester M13 9PL, United Kingdom
| | - G Demeter
- Wigner Research Centre for Physics, 1121 Budapest, Hungary
| | - A C Dexter
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- Lancaster University, Lancaster LA1 4YB, United Kingdom
| | | | | | - J Farmer
- CERN, 1211 Geneva 23, Switzerland
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - A Fasoli
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | | | - R Fonseca
- ISCTE-Instituto Universitéario de Lisboa, 1049-001 Lisbon, Portugal
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - I Furno
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - A Gorn
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk , Russia
| | | | - M Granetzny
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - T Graubner
- Philipps-Universität Marburg, 35032 Marburg, Germany
| | - O Grulke
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
- Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - V Hafych
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - J Henderson
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- Accelerator Science and Technology Centre, ASTeC, STFC Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - M Hüther
- Max Planck Institute for Physics, 80805 Munich, Germany
| | - V Khudiakov
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - S-Y Kim
- CERN, 1211 Geneva 23, Switzerland
- UNIST, Ulsan 44919, Republic of Korea
| | - F Kraus
- Philipps-Universität Marburg, 35032 Marburg, Germany
| | - M Krupa
- CERN, 1211 Geneva 23, Switzerland
| | | | - L Liang
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- University of Manchester, Manchester M13 9PL, United Kingdom
| | - S Liu
- TRIUMF, Vancouver, Canada
| | - N Lopes
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - K Lotov
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk , Russia
| | | | | | | | - K Moon
- UNIST, Ulsan 44919, Republic of Korea
| | | | - M Moreira
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - E Nowak
- CERN, 1211 Geneva 23, Switzerland
| | - C Pakuza
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | | | | | - K Pepitone
- Angstrom Laboratory, Department of Physics and Astronomy, 752 37 Uppsala, Sweden
| | - A Perera
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - A Pukhov
- Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - R L Ramjiawan
- CERN, 1211 Geneva 23, Switzerland
- John Adams Institute, Oxford University, Oxford OX1 3RH, United Kingdom
| | - S Rey
- CERN, 1211 Geneva 23, Switzerland
| | - O Schmitz
- University of Wisconsin, Madison, Wisconsin 53706, USA
| | - F Silva
- INESC-ID, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - L Silva
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - C Stollberg
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
| | - A Sublet
- CERN, 1211 Geneva 23, Switzerland
| | - C Swain
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | | | - N Torrado
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - P Tuev
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk , Russia
| | | | | | - J Vieira
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - M Weidl
- Max Planck Institute for Plasma Physics, 80805 Munich, Germany
| | - C Welsch
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | - M Wendt
- CERN, 1211 Geneva 23, Switzerland
| | - M Wing
- UCL, London WC1 6BT, United Kingdom
| | - J Wolfenden
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
| | | | - G Xia
- Cockcroft Institute, Warrington WA4 4AD, United Kingdom
- University of Manchester, Manchester M13 9PL, United Kingdom
| | - V Yarygova
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk , Russia
| | - M Zepp
- University of Wisconsin, Madison, Wisconsin 53706, USA
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8
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Rebbeck R, Ginsburg KS, Ko CY, Fasoli A, Rusch K, Cai GF, Dong X, Thomas DD, Bers DM, Cornea RL. Synergistic FRET assays for drug discovery targeting RyR2 channels. J Mol Cell Cardiol 2022; 168:13-23. [PMID: 35405106 PMCID: PMC10088286 DOI: 10.1016/j.yjmcc.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/09/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Abstract
A key therapeutic target for heart failure and arrhythmia is the deleterious leak through sarcoplasmic reticulum (SR) ryanodine receptor 2 (RyR2) calcium release channels. We have previously developed methods to detect the pathologically leaky state of RyR2 in adult cardiomyocytes by monitoring RyR2 binding to either calmodulin (CaM) or a biosensor peptide (DPc10). Here, we test whether these complementary binding measurements are effective as high-throughput screening (HTS) assays to discover small molecules that target leaky RyR2. Using FRET, we developed and validated HTS procedures under conditions that mimic a pathological state, to screen the library of 1280 pharmaceutically active compounds (LOPAC) for modulators of RyR2 in cardiac SR membrane preparations. Complementary FRET assays with acceptor-labeled CaM and DPc10 were used for Hit prioritization based on the opposing binding properties of CaM vs. DPc10. This approach narrowed the Hit list to one compound, Ro 90-7501, which altered FRET to suggest increased RyR2-CaM binding and decreased DPc10 binding. Follow-up studies revealed that Ro 90-7501 does not detrimentally affect myocyte Ca2+ transients. Moreover, Ro 90-7501 partially inhibits overall Ca2+ leak, as assessed by Ca2+ sparks in permeabilized rat cardiomyocytes. Together, these results demonstrate (1) the effectiveness of our HTS approach where two complementary assays synergize for Hit ranking and (2) a drug discovery process that combines high-throughput, high-precision in vitro structural assays with in situ myocyte assays of the pathologic RyR2 leak. These provide a drug discovery platform compatible with large-scale HTS campaigns, to identify agents that inhibit RyR2 for therapeutic development.
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Affiliation(s)
- RobynT Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA
| | | | - Christopher Y Ko
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Anna Fasoli
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Katherine Rusch
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA
| | - George F Cai
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA
| | - Xiaoqiong Dong
- Department of Pharmacology, University of California, Davis, CA, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA; Photonic Pharma LLC, Minneapolis, MN, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, MN, USA; Photonic Pharma LLC, Minneapolis, MN, USA.
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9
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Hegyi B, Fasoli A, Ko CY, Van BW, Alim CC, Shen EY, Ciccozzi MM, Tapa S, Ripplinger CM, Erickson JR, Bossuyt J, Bers DM. CaMKII Serine 280 O-GlcNAcylation Links Diabetic Hyperglycemia to Proarrhythmia. Circ Res 2021; 129:98-113. [PMID: 33926209 PMCID: PMC8221539 DOI: 10.1161/circresaha.120.318402] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 04/22/2021] [Accepted: 04/28/2021] [Indexed: 12/16/2022]
Abstract
[Figure: see text].
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MESH Headings
- Action Potentials
- Adult
- Aged
- Animals
- Arrhythmias, Cardiac/enzymology
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/physiopathology
- Biomarkers/blood
- Blood Glucose/metabolism
- Calcium Signaling
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/genetics
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism
- Case-Control Studies
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/enzymology
- Diabetes Mellitus, Experimental/genetics
- Excitation Contraction Coupling
- Female
- Glycosylation
- Heart Rate
- Humans
- Male
- Mice, Inbred C57BL
- Mice, Inbred ICR
- Mice, Transgenic
- Middle Aged
- Mutation
- Myocardial Contraction
- Myocytes, Cardiac/enzymology
- NADPH Oxidase 2/genetics
- NADPH Oxidase 2/metabolism
- Phosphorylation
- Protein Processing, Post-Translational
- Mice
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Affiliation(s)
- Bence Hegyi
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Anna Fasoli
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Christopher Y. Ko
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Benjamin W. Van
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Chidera C. Alim
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Erin Y. Shen
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Marisa M. Ciccozzi
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Srinivas Tapa
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Crystal M. Ripplinger
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Jeffrey R. Erickson
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand (J.R.E.)
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
| | - Donald M. Bers
- Department of Pharmacology, University of California, Davis (B.H., A.F., C.Y.K., B.W.V., C.C.A., E.Y.S., M.M.C., S.T., C.M.R., J.B., D.M.B.)
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10
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Schmidt BS, Salewski M, Reman B, Dendy RO, Moseev D, Ochoukov R, Fasoli A, Baquero-Ruiz M, Järleblad H. Determining 1D fast-ion velocity distribution functions from ion cyclotron emission data using deep neural networks. Rev Sci Instrum 2021; 92:053528. [PMID: 34243325 DOI: 10.1063/5.0041456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/26/2021] [Indexed: 06/13/2023]
Abstract
The relationship between simulated ion cyclotron emission (ICE) signals s and the corresponding 1D velocity distribution function fv⊥ of the fast ions triggering the ICE is modeled using a two-layer deep neural network. The network architecture (number of layers and number of computational nodes in each layer) and hyperparameters (learning rate and number of learning iterations) are fine-tuned using a bottom-up approach based on cross-validation. Thus, the optimal mapping gs;θ of the neural network in terms of the number of nodes, the number of layers, and the values of the hyperparameters, where θ is the learned model parameters, is determined by comparing many different configurations of the network on the same training and test set and choosing the best one based on its average test error. The training and test sets are generated by computing random ICE velocity distribution functions f and their corresponding ICE signals s by modeling the relationship as the linear matrix equation Wf = s. The simulated ICE signals are modeled as edge ICE signals at LHD. The network predictions for f based on ICE signals s are on many simulated ICE signal examples closer to the true velocity distribution function than that obtained by 0th-order Tikhonov regularization, although there might be qualitative differences in which features one technique is better at predicting than the other. Additionally, the network computations are much faster. Adapted versions of the network can be applied to future experimental ICE data to infer fast-ion velocity distribution functions.
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Affiliation(s)
- B S Schmidt
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - M Salewski
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - B Reman
- Laboratoire Plasma et Conversion d'Energie, Université Toulouse, Toulouse, France
| | - R O Dendy
- Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, United Kingdom
| | - D Moseev
- Max-Planck-Institut für Plasmaphysik, Greifswald, Garching, Germany
| | - R Ochoukov
- Max-Planck-Institut für Plasmaphysik, Greifswald, Garching, Germany
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne, Swiss Plasma Center, Lausanne, Switzerland
| | - M Baquero-Ruiz
- École Polytechnique Fédérale de Lausanne, Swiss Plasma Center, Lausanne, Switzerland
| | - H Järleblad
- Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark
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11
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Batsch F, Muggli P, Agnello R, Ahdida CC, Amoedo Goncalves MC, Andrebe Y, Apsimon O, Apsimon R, Bachmann AM, Baistrukov MA, Blanchard P, Braunmüller F, Burrows PN, Buttenschön B, Caldwell A, Chappell J, Chevallay E, Chung M, Cooke DA, Damerau H, Davut C, Demeter G, Deubner HL, Doebert S, Farmer J, Fasoli A, Fedosseev VN, Fiorito R, Fonseca RA, Friebel F, Furno I, Garolfi L, Gessner S, Gorgisyan I, Gorn AA, Granados E, Granetzny M, Graubner T, Grulke O, Gschwendtner E, Hafych V, Helm A, Henderson JR, Hüther M, Kargapolov IY, Kim SY, Kraus F, Krupa M, Lefevre T, Liang L, Liu S, Lopes N, Lotov KV, Martyanov M, Mazzoni S, Medina Godoy D, Minakov VA, Moody JT, Moon K, Morales Guzmán PI, Moreira M, Nechaeva T, Nowak E, Pakuza C, Panuganti H, Pardons A, Perera A, Pucek J, Pukhov A, Ramjiawan RL, Rey S, Rieger K, Schmitz O, Senes E, Silva LO, Speroni R, Spitsyn RI, Stollberg C, Sublet A, Topaloudis A, Torrado N, Tuev PV, Turner M, Velotti F, Verra L, Verzilov VA, Vieira J, Vincke H, Welsch CP, Wendt M, Wing M, Wiwattananon P, Wolfenden J, Woolley B, Xia G, Zepp M, Zevi Della Porta G. Transition between Instability and Seeded Self-Modulation of a Relativistic Particle Bunch in Plasma. Phys Rev Lett 2021; 126:164802. [PMID: 33961468 DOI: 10.1103/physrevlett.126.164802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/18/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
We use a relativistic ionization front to provide various initial transverse wakefield amplitudes for the self-modulation of a long proton bunch in plasma. We show experimentally that, with sufficient initial amplitude [≥(4.1±0.4) MV/m], the phase of the modulation along the bunch is reproducible from event to event, with 3%-7% (of 2π) rms variations all along the bunch. The phase is not reproducible for lower initial amplitudes. We observe the transition between these two regimes. Phase reproducibility is essential for deterministic external injection of particles to be accelerated.
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Affiliation(s)
- F Batsch
- Max Planck Institute for Physics, Munich, Germany
| | - P Muggli
- Max Planck Institute for Physics, Munich, Germany
| | - R Agnello
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | | | - Y Andrebe
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - O Apsimon
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | - R Apsimon
- Cockcroft Institute, Daresbury, United Kingdom
- Lancaster University, Lancaster, United Kingdom
| | - A-M Bachmann
- Max Planck Institute for Physics, Munich, Germany
| | - M A Baistrukov
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - P Blanchard
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | - P N Burrows
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | - B Buttenschön
- Max Planck Institute for Plasma Physics, Greifswald, Germany
| | - A Caldwell
- Max Planck Institute for Physics, Munich, Germany
| | - J Chappell
- University College London, London, United Kingdom
| | | | - M Chung
- Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - D A Cooke
- University College London, London, United Kingdom
| | | | - C Davut
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - G Demeter
- Wigner Research Center for Physics, Budapest, Hungary
| | - H L Deubner
- Philipps-Universität Marburg, Marburg, Germany
| | | | - J Farmer
- Max Planck Institute for Physics, Munich, Germany
- CERN, Geneva, Switzerland
| | - A Fasoli
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | - R Fiorito
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | - R A Fonseca
- ISCTE-Instituto Universitéario de Lisboa, Portugal
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - I Furno
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | - S Gessner
- CERN, Geneva, Switzerland
- SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | | | - A A Gorn
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | | | - M Granetzny
- University of Wisconsin, Madison, Wisconsin, USA
| | - T Graubner
- Philipps-Universität Marburg, Marburg, Germany
| | - O Grulke
- Max Planck Institute for Plasma Physics, Greifswald, Germany
- Technical University of Denmark, Lyngby, Denmark
| | | | - V Hafych
- Max Planck Institute for Physics, Munich, Germany
| | - A Helm
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - J R Henderson
- Cockcroft Institute, Daresbury, United Kingdom
- Accelerator Science and Technology Centre, ASTeC, STFC Daresbury Laboratory, Warrington, United Kingdom
| | - M Hüther
- Max Planck Institute for Physics, Munich, Germany
| | - I Yu Kargapolov
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - S-Y Kim
- Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - F Kraus
- Philipps-Universität Marburg, Marburg, Germany
| | | | | | - L Liang
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - S Liu
- TRIUMF, Vancouver, Canada
| | - N Lopes
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - K V Lotov
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - M Martyanov
- Max Planck Institute for Physics, Munich, Germany
| | | | | | - V A Minakov
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - J T Moody
- Max Planck Institute for Physics, Munich, Germany
| | - K Moon
- Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | | | - M Moreira
- CERN, Geneva, Switzerland
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - T Nechaeva
- Max Planck Institute for Physics, Munich, Germany
| | | | - C Pakuza
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | | | | | - A Perera
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | - J Pucek
- Max Planck Institute for Physics, Munich, Germany
| | - A Pukhov
- Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - R L Ramjiawan
- CERN, Geneva, Switzerland
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | - S Rey
- CERN, Geneva, Switzerland
| | - K Rieger
- Max Planck Institute for Physics, Munich, Germany
| | - O Schmitz
- University of Wisconsin, Madison, Wisconsin, USA
| | - E Senes
- CERN, Geneva, Switzerland
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | - L O Silva
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - R I Spitsyn
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - C Stollberg
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | | | - N Torrado
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - P V Tuev
- Novosibirsk State University, Novosibirsk, Russia
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - M Turner
- CERN, Geneva, Switzerland
- Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | | | - L Verra
- Max Planck Institute for Physics, Munich, Germany
- CERN, Geneva, Switzerland
- Technical University Munich, Munich, Germany
| | | | - J Vieira
- GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - C P Welsch
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | | | - M Wing
- University College London, London, United Kingdom
| | | | - J Wolfenden
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | | | - G Xia
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - M Zepp
- University of Wisconsin, Madison, Wisconsin, USA
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Baquero-Ruiz M, Coda S, Dolizy F, Duval B, Fasoli A, Ferrara A, Maccallini E, Manini P, Martin Y, Mura M, Reimerdes H, Siviero F. Non-evaporable getter pump operations in the TCV tokamak. Fusion Engineering and Design 2021. [DOI: 10.1016/j.fusengdes.2021.112267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ghayoumi B, Fasoli A, Ko CY, Bers DM, Sato D. Post-Translational Modifications Promote Functional Heterogeneity in Cardiac Myocytes. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Braunmüller F, Nechaeva T, Adli E, Agnello R, Aladi M, Andrebe Y, Apsimon O, Apsimon R, Bachmann AM, Baistrukov MA, Batsch F, Bergamaschi M, Blanchard P, Burrows PN, Buttenschön B, Caldwell A, Chappell J, Chevallay E, Chung M, Cooke DA, Damerau H, Davut C, Demeter G, Deubner LH, Dexter A, Djotyan GP, Doebert S, Farmer J, Fasoli A, Fedosseev VN, Fiorito R, Fonseca RA, Friebel F, Furno I, Garolfi L, Gessner S, Goddard B, Gorgisyan I, Gorn AA, Granados E, Granetzny M, Grulke O, Gschwendtner E, Hafych V, Hartin A, Helm A, Henderson JR, Howling A, Hüther M, Jacquier R, Jolly S, Kargapolov IY, Kedves MÁ, Keeble F, Kelisani MD, Kim SY, Kraus F, Krupa M, Lefevre T, Li Y, Liang L, Liu S, Lopes N, Lotov KV, Martyanov M, Mazzoni S, Medina Godoy D, Minakov VA, Moody JT, Morales Guzmán PI, Moreira M, Muggli P, Panuganti H, Pardons A, Peña Asmus F, Perera A, Petrenko A, Pucek J, Pukhov A, Ráczkevi B, Ramjiawan RL, Rey S, Ruhl H, Saberi H, Schmitz O, Senes E, Sherwood P, Silva LO, Spitsyn RI, Tuev PV, Turner M, Velotti F, Verra L, Verzilov VA, Vieira J, Welsch CP, Williamson B, Wing M, Wolfenden J, Woolley B, Xia G, Zepp M, Zevi Della Porta G. Proton Bunch Self-Modulation in Plasma with Density Gradient. Phys Rev Lett 2020; 125:264801. [PMID: 33449727 DOI: 10.1103/physrevlett.125.264801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/10/2020] [Accepted: 11/10/2020] [Indexed: 06/12/2023]
Abstract
We study experimentally the effect of linear plasma density gradients on the self-modulation of a 400 GeV proton bunch. Results show that a positive or negative gradient increases or decreases the number of microbunches and the relative charge per microbunch observed after 10 m of plasma. The measured modulation frequency also increases or decreases. With the largest positive gradient we observe two frequencies in the modulation power spectrum. Results are consistent with changes in wakefields' phase velocity due to plasma density gradients adding to the slow wakefields' phase velocity during self-modulation growth predicted by linear theory.
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Affiliation(s)
| | - T Nechaeva
- Belarusian State University, Minsk, Belarus
| | - E Adli
- University of Oslo, Oslo, Norway
| | - R Agnello
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - M Aladi
- Wigner Research Center for Physics, Budapest, Hungary
| | - Y Andrebe
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - O Apsimon
- Cockcroft Institute, Daresbury, United Kingdom
- Lancaster University, Lancaster, United Kingdom
| | - R Apsimon
- Cockcroft Institute, Daresbury, United Kingdom
- Lancaster University, Lancaster, United Kingdom
| | - A-M Bachmann
- Max Planck Institute for Physics, Munich, Germany
- CERN, Geneva, Switzerland
- Technical University Munich, Munich, Germany
| | - M A Baistrukov
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - F Batsch
- Max Planck Institute for Physics, Munich, Germany
- CERN, Geneva, Switzerland
- Technical University Munich, Munich, Germany
| | | | - P Blanchard
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - P N Burrows
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | - B Buttenschön
- Max Planck Institute for Plasma Physics, Greifswald, Germany
| | - A Caldwell
- Max Planck Institute for Physics, Munich, Germany
| | | | | | - M Chung
- UNIST, Ulsan, Republic of Korea
| | | | | | - C Davut
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - G Demeter
- Wigner Research Center for Physics, Budapest, Hungary
| | - L H Deubner
- Philipps-Universität Marburg, Marburg, Germany
| | - A Dexter
- Cockcroft Institute, Daresbury, United Kingdom
- Lancaster University, Lancaster, United Kingdom
| | - G P Djotyan
- Wigner Research Center for Physics, Budapest, Hungary
| | | | - J Farmer
- Max Planck Institute for Physics, Munich, Germany
- CERN, Geneva, Switzerland
| | - A Fasoli
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | - R Fiorito
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | - R A Fonseca
- ISCTE-Instituto Universitéario de Lisboa, Lisbon, Portugal
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - I Furno
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | - S Gessner
- CERN, Geneva, Switzerland
- SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | | | | | - A A Gorn
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | | | - M Granetzny
- University of Wisconsin, Madison, Wisconsin, USA
| | - O Grulke
- Max Planck Institute for Plasma Physics, Greifswald, Germany
- Technical University of Denmark, Lyngby, Denmark
| | | | - V Hafych
- Max Planck Institute for Physics, Munich, Germany
| | | | - A Helm
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - J R Henderson
- Cockcroft Institute, Daresbury, United Kingdom
- Accelerator Science and Technology Centre, ASTeC, STFC Daresbury Laboratory, Warrington, United Kingdom
| | - A Howling
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - M Hüther
- Max Planck Institute for Physics, Munich, Germany
| | - R Jacquier
- Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | | | - I Yu Kargapolov
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - M Á Kedves
- Wigner Research Center for Physics, Budapest, Hungary
| | | | | | - S-Y Kim
- UNIST, Ulsan, Republic of Korea
| | - F Kraus
- Philipps-Universität Marburg, Marburg, Germany
| | | | | | - Y Li
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - L Liang
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - S Liu
- TRIUMF, Vancouver, Canada
| | - N Lopes
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - K V Lotov
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - M Martyanov
- Max Planck Institute for Physics, Munich, Germany
| | | | | | - V A Minakov
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - J T Moody
- Max Planck Institute for Physics, Munich, Germany
| | | | - M Moreira
- CERN, Geneva, Switzerland
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - P Muggli
- Max Planck Institute for Physics, Munich, Germany
| | | | | | - F Peña Asmus
- Max Planck Institute for Physics, Munich, Germany
- Technical University Munich, Munich, Germany
| | - A Perera
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | - A Petrenko
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
| | - J Pucek
- Max Planck Institute for Physics, Munich, Germany
| | - A Pukhov
- Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - B Ráczkevi
- Wigner Research Center for Physics, Budapest, Hungary
| | - R L Ramjiawan
- CERN, Geneva, Switzerland
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | - S Rey
- CERN, Geneva, Switzerland
| | - H Ruhl
- Ludwig-Maximilians-Universität, Munich, Germany
| | | | - O Schmitz
- University of Wisconsin, Madison, Wisconsin, USA
| | - E Senes
- CERN, Geneva, Switzerland
- John Adams Institute, Oxford University, Oxford, United Kingdom
| | | | - L O Silva
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - R I Spitsyn
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | - P V Tuev
- Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
| | | | | | - L Verra
- Max Planck Institute for Physics, Munich, Germany
- CERN, Geneva, Switzerland
- Technical University Munich, Munich, Germany
| | | | - J Vieira
- GoLP/Instituto de Plasmas e Fusáo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - C P Welsch
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | - B Williamson
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - M Wing
- UCL, London, United Kingdom
| | - J Wolfenden
- Cockcroft Institute, Daresbury, United Kingdom
- University of Liverpool, Liverpool, United Kingdom
| | | | - G Xia
- Cockcroft Institute, Daresbury, United Kingdom
- University of Manchester, Manchester, United Kingdom
| | - M Zepp
- University of Wisconsin, Madison, Wisconsin, USA
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Baquero-Ruiz M, Fasoli A, Furno I, Manke F, Ricci P. Persistent random walks of charged particles across magnetic field lines. Phys Rev E 2020; 102:053206. [PMID: 33327121 DOI: 10.1103/physreve.102.053206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/11/2020] [Indexed: 11/07/2022]
Abstract
We investigate the time evolution of the mean location and variance of a charged particle subject to random collisions that are Poisson distributed. The particle moves on a plane and is subject to a magnetic field applied perpendicular to the plane, so it is constrained to move in circles in the absence of collisions. We develop a procedure that yields analytic expressions of the mean and variance. These results are valid for arbitrary times after the start of the walk, including early on when, on average, less than one collision is expected. As an example of their applicability, we use these expressions to model experimental results and simulations of suprathermal ions propagating in a turbulent plasma in TORPEX (the TORoidal Plasma EXperiment).
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Affiliation(s)
- M Baquero-Ruiz
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - F Manke
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Ricci
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
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16
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Micheletti P, Baquero-Ruiz M, Manke F, Furno I, Ricci P, Fasoli A, Bowen P, Morais C, Zhao W. Cathodoluminescent screen imaging system for seeded blob detection in toroidal plasma experiment. Rev Sci Instrum 2020; 91:053501. [PMID: 32486748 DOI: 10.1063/1.5123038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
We designed and built a diagnostic based on a cathodoluminescent screen for the detection of turbulent plasma structures with high spatial resolution. The screen is coated with a low threshold energy cathodoluminescent powder that emits light when exposed to a plasma. The emitted light is imaged with a fast frame camera combined with an image intensifier and an optical bandpass filter. The diagnostic is used to study turbulent structures and seeded blobs. The results are analyzed with pattern recognition algorithms to track the turbulent structures and study their evolution in time.
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Affiliation(s)
- P Micheletti
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - M Baquero-Ruiz
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - F Manke
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Ricci
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Bowen
- École Polytechnique Fédérale de Lausanne (EPFL), Powder Technology Laboratory (LTP), CH-1015 Lausanne, Switzerland
| | - C Morais
- École Polytechnique Fédérale de Lausanne (EPFL), Powder Technology Laboratory (LTP), CH-1015 Lausanne, Switzerland
| | - W Zhao
- École Polytechnique Fédérale de Lausanne (EPFL), Powder Technology Laboratory (LTP), CH-1015 Lausanne, Switzerland
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17
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Hegyi B, Fasoli A, Ko CY, Ciccozzi MM, Tapa S, Van BW, Shen EY, Baidar S, Bossuyt J, Ripplinger CM, Bers DM. O-Glycosylation of Camkii at Serine 280 Promotes Cardiac Arrhythmias in Diabetic Hyperglycemia. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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18
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Manke F, Baquero-Ruiz M, Furno I, Chellaï O, Fasoli A, Ricci P. Truncated Lévy motion through path integrals and applications to nondiffusive suprathermal ion transport. Phys Rev E 2019; 100:052122. [PMID: 31869979 DOI: 10.1103/physreve.100.052122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Indexed: 11/07/2022]
Abstract
Fractional Levy motion has been derived from its generalized Langevin equation via path integrals in earlier works and has since proven to be a useful model for nonlocal and non-Markovian processes, especially in the context of nondiffusive transport. Here, we generalize the approach to treat tempered Lévy distributions and derive the propagator and diffusion equation of truncated asymmetrical fractional Levy motion via path integrals. The model now recovers exponentially tempered tails above a chosen scale in the propagator, and therefore finite moments at all orders. Concise analytical expressions for its variance, skewness, and kurtosis are derived as a function of time. We then illustrate the versatility of this model by applying it to simulations of the turbulent transport of fast ions in the TORPEX basic plasma device.
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Affiliation(s)
- F Manke
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - M Baquero-Ruiz
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - O Chellaï
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Ricci
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
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Baquero-Ruiz M, Manke F, Furno I, Fasoli A, Ricci P. Particle transport at arbitrary timescales with Poisson-distributed collisions. Phys Rev E 2019; 100:052134. [PMID: 31870020 DOI: 10.1103/physreve.100.052134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Indexed: 06/10/2023]
Abstract
We develop a model to investigate the time evolution of the mean location and variance of a random walker subject to Poisson-distributed collisions at constant rate. The collisions are instantaneous velocity changes where a new value of velocity is generated from a model probability function. The walker is persistent, which means that it moves at constant velocity between collisions. We study three different cases of velocity transition functions and compute the transport properties from the evolution of the variance. We observe that transport can change character over time and that early times show features that, in general, depend on the initial conditions of the walker.
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Affiliation(s)
- M Baquero-Ruiz
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - F Manke
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Ricci
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
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Vallar M, Karpushov A, Agostini M, Bolzonella T, Coda S, Duval B, Fasoli A, Galperti C, Garcia J, Geiger B, Goodman T, Jacquier R, Labit B, Maurizio R, Pimazzoni A, Piron C, Serianni G, Testa D, Valisa M, Veltri P, Vianello N. Status, scientific results and technical improvements of the NBH on TCV tokamak. Fusion Engineering and Design 2019. [DOI: 10.1016/j.fusengdes.2019.01.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dowson S, Dorling S, Sheikh H, Blackman T, Jones G, Goodyear A, Puglia P, Blanchard P, Fasoli A, Testa D, Fil N, Aslanyan V, Porkolab M, Woskov P, De Sa WP, Galvao R, Ruchko L, Figueiredo J, Von Thun CP. The JET upgraded toroidal Alfvén Eigenmode Diagnostic System. Fusion Engineering and Design 2019. [DOI: 10.1016/j.fusengdes.2019.04.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Manke F, Baquero-Ruiz M, Furno I, Chellaï O, Fasoli A, Ricci P. Time intermittency in nondiffusive transport regimes of suprathermal ions in turbulent plasmas. Phys Rev E 2019; 99:053208. [PMID: 31212579 DOI: 10.1103/physreve.99.053208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Indexed: 06/09/2023]
Abstract
Intermittent phenomena have long been studied in the context of nondiffusive transport across a variety of fields. In the TORPEX device, the cross-field spreading of an injected suprathermal ion beam by electrostatic plasma turbulence can access different nondiffusive transport regimes. A comprehensive set of suprathermal ion time series has been acquired, and time intermittency quantified by their skewness. Values distinctly above background level are found across all observed transport regimes. Intermittency tends to increase toward quasi- and superdiffusion and for longer propagation times of the suprathermal ions. The specific prevalence of intermittency is determined by the meandering motion of the instantaneous ion beam. We demonstrate the effectiveness of an analytical model developed to predict local intermittency from the time-average beam. This model might thus be of direct interest for similar systems, e.g., in beam physics, or meandering flux-rope models for solar energetic particle propagation. More generally, it illustrates the importance of identifying the system-specific sources of time-intermittent behavior when analyzing nondiffusive transport.
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Affiliation(s)
- F Manke
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - M Baquero-Ruiz
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - O Chellaï
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Ricci
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
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Cunietti E, Gandini R, Gandini MC, Locatelli E, Viola P, Chinea B, Fasoli A. Anionic Glycoproteins and their Hexosamine Content in Neoplastic Patients: Relationships with the Clinical Stage and the Course of the Disease. Tumori 2018; 69:503-8. [PMID: 6665873 DOI: 10.1177/030089168306900603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In 40 healthy subjects, in 47 non-cancer patients, and in 142 cancer patients, perchloric acid-soluble glycoproteins (PASG) and hexosamines were determined to investigate their tumor specificity and correlation with the tumor mass. Cancer patients were divided into three subgroups: CI, no evidence of cancer (after radical surgery); CII, locoregional disease; CIII, widespread metastatic disease. There was no statistically significant difference in PASG among normals, non-cancer and CI patients; hexosamines in non-cancer and in CI patients were higher (P < 0.002) than in normals; both PASG and hexosamines were significantly higher in CII and CIII patients than in normals (P < 0.001). In the CI group, 62% of patients who relapsed within 10 months after surgery had high hexosamine values, whereas 69% of patients who did not relapse showed normal levels (P < 0.05). PASG and hexosamines significantly increased with cancer progression and decreased when objective response to treatment was achieved. They are not tumor specific, but seem to be related to the tumor burden; hexosamines seem to have some prognostic value.
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Giannini E, Borro P, Botta F, Chiarbonello B, Fasoli A, Malfatti F, Romagnoli P, Testa E, Risso D, Lantieri PB, Antonucci A, Boccato M, Milone S, Testa R. Cholestasis is the Main Determinant of Abnormal CA 19–9 Levels in Patients with Liver Cirrhosis. Int J Biol Markers 2018; 15:226-30. [PMID: 11012098 DOI: 10.1177/172460080001500304] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background/Aims Altered CA19–9 levels are commonly found in patients with liver cirrhosis though a clear explanation for this finding has not yet been given. The aim of this study was to investigate whether CA19–9 levels might be related to alterations in biochemical parameters and/or to functional impairment in cirrhotic patients with and without hepatocellular carcinoma. Methods: We studied 126 patients with liver cirrhosis, 60 of whom also had hepatocellular carcinoma. CA19–9 values were related to clinical, biochemical and functional parameters. In half of the patients CA19–9 levels were related to the monoethylglycinexylidide test, which is a dynamic liver function test. Results In more than half the cases CA19–9 values were above the upper limit. Liver function worsening as assessed by Child-Pugh's score and monoethylglycinexylidide test did not seem to influence the alteration of the marker. By contrast, in univariate analysis CA19–9 correlated with aminotransferases, γ-glutamyltransferase and alkaline phosphatase. Multivariate analysis showed that besides alkaline phosphatase also the presence of hepatocellular carcinoma might influence the alteration of CA19–9, although the marker was of no use for the diagnosis of liver cancer in patients with altered though not diagnostic α-fetoprotein levels. Conclusions In our study we confirmed the correlation of CA19–9 levels with cholestasis and cytolysis parameters. Moreover, we found no association between CA19–9 levels and impaired liver function as assessed by means of the Child-Pugh's score and the monoethylglycinexylidide test, which is cholestasis-independent and explores liver metabolic and clearance activities. The cholestatic picture that characterizes liver cirrhosis might enhance the expression and passage of the marker from the bile to the blood. The addition of CA19–9 assessment is not useful for the diagnosis of hepatocellular carcinoma in patients with non-diagnostic levels of α-fetoprotein. Caution should therefore be used when evaluating CA19–9 in cirrhotic patients with cholestasis, since false positive results may occur.
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Affiliation(s)
- E Giannini
- Department of Internal Medicine, University of Genoa, Italy
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Reimerdes H, Alberti S, Blanchard P, Bruzzone P, Chavan R, Coda S, Duval B, Fasoli A, Labit B, Lipschultz B, Lunt T, Martin Y, Moret JM, Sheikh U, Sudki B, Testa D, Theiler C, Toussaint M, Uglietti D, Vianello N, Wischmeier M. TCV divertor upgrade for alternative magnetic configurations. Nuclear Materials and Energy 2017. [DOI: 10.1016/j.nme.2017.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Snipes JA, Basse N, Bonoli P, Boswell C, Edlund E, Fasoli A, Granetz RS, Lin L, Lin Y, Parker R, Porkolab M, Sears J, Tang V, Wukitch S. Energetic Particle Physics Studies on Alcator C-Mod. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- J. A. Snipes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - N. Basse
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - P. Bonoli
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - C. Boswell
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. Edlund
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. Fasoli
- CRPP, Association Euratom–Confederation Suisse, EPFL Lausanne, Switzerland
| | - R. S. Granetz
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - L. Lin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - Y. Lin
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - R. Parker
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - M. Porkolab
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - J. Sears
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - V. Tang
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
| | - S. Wukitch
- Plasma Science and Fusion Center, Massachusetts Institute of Technology Cambridge, Massachusetts 02139
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Donné AJH, Fasoli A, Ferron J, Gonçalves B, Jardin S, Miura Y, Noterdaeme JM, Ozeki T. Summary of the International Energy Agency Workshop on Burning Plasma Physics and Simulation. Fusion Science and Technology 2017. [DOI: 10.13182/fst06-a1088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A. J. H. Donné
- FOM-Institute for Plasma Physics Rijnhuizen Association Euratom-FOM Partner in the Trilateral Euregio Cluster P.O. Box 1207, 3430 BE Nieuwegein, The Netherlands
| | - A. Fasoli
- CRPP-EPFL, Association Euratom-Swiss Confederation Lausanne, Switzerland
| | - J. Ferron
- General Atomics, San Diego, California
| | | | - S. Jardin
- Princeton Plasma Physics Laboratory Princeton, New Jersey
| | - Y. Miura
- Japan Atomic Energy Research Institute Naka, Japan
| | - J.-M. Noterdaeme
- Max Planck Institute for Plasmaphysics Euratom Association, Garching, Germany and University Gent, EESA Department, Gent, Belgium
| | - T. Ozeki
- Japan Atomic Energy Research Institute Naka, Japan
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Sharapov SE, Eriksson LG, Fasoli A, Gorini G, Källne J, Kiptily VG, Korotkov AA, Murari A, Pinches SD, Testa DS, Thomas PR. Chapter 5: Burning Plasma Studies at JET. Fusion Science and Technology 2017. [DOI: 10.13182/fst08-a1745] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S. E. Sharapov
- Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - L.-G. Eriksson
- Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, France
| | - A. Fasoli
- CRPP/EPFL, Association EURATOM-Confédération Suisse, Lausanne, Switzerland
| | - G. Gorini
- Istituto di Fisica del Plasma, EURATOM-ENEA-CNR Association, Milan, Italy
| | - J. Källne
- INF, Uppsala University, Association Euratom-VR, Uppsala, Sweden
| | - V. G. Kiptily
- Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - A. A. Korotkov
- Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - A. Murari
- Consorzio RFX-Associazione Euratom-ENEA sulla Fusione, Padova, Italy
| | - S. D. Pinches
- Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United Kingdom
| | - D. S. Testa
- CRPP/EPFL, Association EURATOM-Confédération Suisse, Lausanne, Switzerland
| | - P. R. Thomas
- Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, France
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Fasoli A, Dang J, Johnson JS, Gouw AH, Fogli Iseppe A, Ishida AT. Somatic and neuritic spines on tyrosine hydroxylase-immunopositive cells of rat retina. J Comp Neurol 2017; 525:1707-1730. [PMID: 28035673 DOI: 10.1002/cne.24166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 12/13/2016] [Accepted: 12/27/2016] [Indexed: 12/27/2022]
Abstract
Dopamine- and tyrosine hydroxylase-immunopositive cells (TH cells) modulate visually driven signals as they flow through retinal photoreceptor, bipolar, and ganglion cells. Previous studies suggested that TH cells release dopamine from varicose axons arborizing in the inner and outer plexiform layers after glutamatergic synapses depolarize TH cell dendrites in the inner plexiform layer and these depolarizations propagate to the varicosities. Although it has been proposed that these excitatory synapses are formed onto appendages resembling dendritic spines, spines have not been found on TH cells of most species examined to date or on TH cell somata that release dopamine when exposed to glutamate receptor agonists. By use of protocols that preserve proximal retinal neuron morphology, we have examined the shape, distribution, and synapse-related immunoreactivity of adult rat TH cells. We report here that TH cell somata, tapering and varicose inner plexiform layer neurites, and varicose outer plexiform layer neurites all bear spines, that some of these spines are immunopositive for glutamate receptor and postsynaptic density proteins (viz., GluR1, GluR4, NR1, PSD-95, and PSD-93), that TH cell somata and tapering neurites are also immunopositive for a γ-aminobutyric acid (GABA) receptor subunit (GABAA Rα1 ), and that a synaptic ribbon-specific protein (RIBEYE) is found adjacent to some colocalizations of GluR1 and TH in the inner plexiform layer. These results identify previously undescribed sites at which glutamatergic and GABAergic inputs may stimulate and inhibit dopamine release, especially at somata and along varicose neurites that emerge from these somata and arborize in various levels of the retina. J. Comp. Neurol. 525:1707-1730, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Anna Fasoli
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - James Dang
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - Jeffrey S Johnson
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - Aaron H Gouw
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - Alex Fogli Iseppe
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California
| | - Andrew T Ishida
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, California.,Department of Ophthalmology and Vision Science, University of California, Sacramento, California
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Baquero-Ruiz M, Avino F, Chellai O, Fasoli A, Furno I, Jacquier R, Manke F, Patrick S. Dual Langmuir-probe array for 3D plasma studies in TORPEX. Rev Sci Instrum 2016; 87:113504. [PMID: 27910384 DOI: 10.1063/1.4968024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/06/2016] [Indexed: 06/06/2023]
Abstract
We have designed and installed a new Langmuir-probe (LP) array diagnostic to determine basic three-dimensional (3D) features of plasmas in TORPEX. The diagnostic consists of two identical LP arrays, placed on opposite sides of the apparatus, which provide comprehensive coverage of the poloidal cross section at the two different toroidal locations. Cross correlation studies of signals from the arrays provide a basic way to extract 3D information from the plasmas, as experiments show. Moreover, the remarkable signal-to-noise performance of the front-end electronics allows us to follow a different approach in which we combine information from all probes in both arrays to reconstruct elementary 3D plasma structures at each acquisition time step. Then, through data analysis, we track the structures as they evolve in time. The LP arrays include a linear-motion mechanism that can displace radially the probes located on the low field side for experiments that require fine-tuning of the probe locations, and for operational compatibility with the recently installed in-vessel toroidal conductor.
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Affiliation(s)
- M Baquero-Ruiz
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - F Avino
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - O Chellai
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - I Furno
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - R Jacquier
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - F Manke
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - S Patrick
- Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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31
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Avino F, Fasoli A, Furno I, Ricci P, Theiler C. X-Point Effect on Plasma Blob Dynamics. Phys Rev Lett 2016; 116:105001. [PMID: 27015485 DOI: 10.1103/physrevlett.116.105001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 06/05/2023]
Abstract
Plasma blob dynamics on the high-field side in the proximity of a magnetic field null (X point) is investigated in TORPEX. A significant acceleration of the blobs towards the X point is observed. Close to the X point the blobs break apart. The E×B drifts associated with the blobs are measured, isolating the background drift component from the fluctuating contribution of the blob internal potential dipole. The time evolution of the latter is consistent with the fast blob dynamics. An analytical model based on charge conservation is derived for the potential dipole, including ion polarization, diamagnetic, and parallel currents. In the vicinity of the X point, a crucial role in determining the blob motion is played by the decrease of the poloidal magnetic field intensity. This variation increases the connection length that short circuits the potential dipole of the blob. Good quantitative agreement is found between the model and the experimental data in the initial accelerating phase of the blob dynamics.
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Affiliation(s)
- F Avino
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - I Furno
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - P Ricci
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
| | - C Theiler
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015 Lausanne, Switzerland
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32
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Aquila M, Benedusi M, Fasoli A, Rispoli G. Characterization of Zebrafish Green Cone Photoresponse Recorded with Pressure-Polished Patch Pipettes, Yielding Efficient Intracellular Dialysis. PLoS One 2015; 10:e0141727. [PMID: 26513584 PMCID: PMC4626105 DOI: 10.1371/journal.pone.0141727] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/12/2015] [Indexed: 11/18/2022] Open
Abstract
The phototransduction enzymatic cascade in cones is less understood than in rods, and the zebrafish is an ideal model with which to investigate vertebrate and human vision. Therefore, here, for the first time, the zebrafish green cone photoresponse is characterized also to obtain a firm basis for evaluating how it is modulated by exogenous molecules. To this aim, a powerful method was developed to obtain long-lasting recordings with low access resistance, employing pressure-polished patch pipettes. This method also enabled fast, efficient delivery of molecules via a perfusion system coupled with pulled quartz or plastic perfusion tubes, inserted very close to the enlarged pipette tip. Sub-saturating flashes elicited responses in different cells with similar rising phase kinetics but with very different recovery kinetics, suggesting the existence of physiologically distinct cones having different Ca2+ dynamics. Theoretical considerations demonstrate that the different recovery kinetics can be modelled by simulating changes in the Ca2+-buffering capacity of the outer segment. Importantly, the Ca2+-buffer action preserves the fast response rising phase, when the Ca2+-dependent negative feedback is activated by the light-induced decline in intracellular Ca2+.
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Affiliation(s)
- Marco Aquila
- Department of Life Science and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mascia Benedusi
- Department of Life Science and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Anna Fasoli
- Department of Life Science and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Giorgio Rispoli
- Department of Life Science and Biotechnology, University of Ferrara, Ferrara, Italy
- * E-mail:
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33
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Bovet A, Fasoli A, Ricci P, Furno I, Gustafson K. Nondiffusive transport regimes for suprathermal ions in turbulent plasmas. Phys Rev E Stat Nonlin Soft Matter Phys 2015; 91:041101. [PMID: 25974432 DOI: 10.1103/physreve.91.041101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Indexed: 06/04/2023]
Abstract
The understanding of the transport of suprathermal ions in the presence of turbulence is important for fusion plasmas in the burning regime that will characterize reactors, and for space plasmas to understand the physics of particle acceleration. Here, three-dimensional measurements of a suprathermal ion beam in the toroidal plasma device TORPEX are presented. These measurements demonstrate, in a turbulent plasma, the existence of subdiffusive and superdiffusive transport of suprathermal ions, depending on their energy. This result stems from the unprecedented combination of uniquely resolved measurements and first-principles numerical simulations that reveal the mechanisms responsible for the nondiffusive transport. The transport regime is determined by the interaction of the suprathermal ion orbits with the turbulent plasma dynamics, and is strongly affected by the ratio of the suprathermal ion energy to the background plasma temperature.
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Affiliation(s)
- A Bovet
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - P Ricci
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - K Gustafson
- École Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Computational Systems Biology, Institute of Bioengineering, School of Life Sciences, CH-1015 Lausanne, Switzerland
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Bovet A, Fasoli A, Furno I. Time-Resolved Measurements of Suprathermal Ion Transport Induced by Intermittent Plasma Blob Filaments. Phys Rev Lett 2014; 113:225001. [PMID: 25494075 DOI: 10.1103/physrevlett.113.225001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Indexed: 06/04/2023]
Abstract
Suprathermal ion turbulent transport in magnetized plasmas is generally nondiffusive, ranging from subdiffusive to superdiffusive depending on the interplay of the turbulent structures and the suprathermal ion orbits. Here, we present time-resolved measurements of the cross-field suprathermal ion transport in a toroidal magnetized turbulent plasma. Measurements in the superdiffusive regime are characterized by a higher intermittency than in the subdiffusive regime. Using conditional averaging, we show that, when the transport is superdiffusive, suprathermal ions are transported by intermittent field-elongated turbulent structures that are radially propagating.
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Affiliation(s)
- A Bovet
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - I Furno
- École Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
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Avino F, Fasoli A, Furno I. The new TORPEX in-vessel toroidal conductor for the generation of a poloidal magnetic field. Rev Sci Instrum 2014; 85:033506. [PMID: 24689584 DOI: 10.1063/1.4868588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
TORoidal Plasma EXperiment (TORPEX) is a Simple Magnetized Torus featuring open helical magnetic field lines obtained from the superposition of a small vertical component on the main toroidal field. This work introduces the experimental setup developed to include a poloidal magnetic field. The toroidal and poloidal fields generate a rotational transform, making the magnetic geometry of TORPEX closer to that of a tokamak. This upgrade opens the possibility to deal with closed and open flux surfaces, as well as with the transition region across the last closed flux surface. The main technical solutions are discussed together with the physical considerations at the basis of the system design. Selected examples of the magnetic configurations accessible with the set of magnetic field coils available on TORPEX are discussed, ranging from single-null X-points to magnetic snowflakes. The simplest magnetic configuration of quasi-circular concentric flux surfaces is tested experimentally. Measurements of the two-dimensional electron plasma density profiles and the particle confinement time are presented, together with the first steps towards the understanding of plasma production mechanisms.
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Affiliation(s)
- F Avino
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - A Fasoli
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
| | - I Furno
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne, Switzerland
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Aquila M, Dell’Orco D, Fasoli A, Benedusi M, Fries R, Scholten A, Kremmer E, Koch KW, Rispoli G. Real-Time Modulation of Zebrafish Cone Phototransduction by Whole-Cell Delivery of zGCAP3 and of its Monoclonal Antibody. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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37
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Eshetua WW, Porte L, Fasoli A, Sauter O, Coda S, Goodman TP. Vertical Electron Cyclotron Emission Diagnostic for TCV Plasmas. EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20123203011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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38
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Theiler C, Furno I, Loizu J, Fasoli A. Convective cells and blob control in a simple magnetized plasma. Phys Rev Lett 2012; 108:065005. [PMID: 22401080 DOI: 10.1103/physrevlett.108.065005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Indexed: 05/31/2023]
Abstract
Blob control by creating convective cells using biased electrodes is demonstrated in simple magnetized toroidal plasmas. A two-dimensional array of electrodes is installed on a metal limiter to obtain different biasing schemes. Detailed two-dimensional measurements across the magnetic field reveal the formation of a convective cell, which shows a high degree of uniformity along the magnetic field. Depending on the biasing scheme, radial and vertical blob velocities can be varied significantly. A high level of cross-field currents limits the achievable potential variations to values well below the applied bias voltage. Furthermore, the strongest potential variations are not induced along the biased flux tube, but at a position shifted in the direction of plasma flows.
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Affiliation(s)
- C Theiler
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, Lausanne, Switzerland
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Gustafson K, Ricci P, Furno I, Fasoli A. Nondiffusive suprathermal ion transport in simple magnetized toroidal plasmas. Phys Rev Lett 2012; 108:035006. [PMID: 22400754 DOI: 10.1103/physrevlett.108.035006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 05/31/2023]
Abstract
We investigate suprathermal ion dynamics in simple magnetized toroidal plasmas in the presence of electrostatic turbulence driven by the ideal interchange instability. Turbulent fields from fluid simulations are used in the nonrelativistic equation of ion motion to compute suprathermal tracer ion trajectories. Suprathermal ion dispersion starts with a brief ballistic phase, during which particles do not interact with the plasma, followed by a turbulence interaction phase. In this one simple system, we observe the entire spectrum of suprathermal ion dynamics, from subdiffusion to superdiffusion, depending on beam energy and turbulence amplitude. We estimate the duration of the ballistic phase and identify basic mechanisms during the interaction phase that determine the dependencies of the character of suprathermal ion dispersion upon the beam energy and turbulence fluctuation amplitude.
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Affiliation(s)
- K Gustafson
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, CH-1015 Lausanne, Switzerland
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Furno I, Spolaore M, Theiler C, Vianello N, Cavazzana R, Fasoli A. Direct two-dimensional measurements of the field-aligned current associated with plasma blobs. Phys Rev Lett 2011; 106:245001. [PMID: 21770576 DOI: 10.1103/physrevlett.106.245001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Indexed: 05/31/2023]
Abstract
In simple magnetized toroidal plasmas, field-aligned blobs originate from ideal interchange waves and propagate radially outward under the effect of ∇B and curvature induced E×B drifts. We report on the first experimental two-dimensional measurements of the field-aligned current associated with blobs, whose ends terminate on a conducting limiter. A dipolar structure of the current density is measured, which originates from ∇B and curvature induced polarization of the blob and is consistent with sheath boundary conditions. The dipole is strongly asymmetric due to the nonlinear dependence of the current density at the sheath edge upon the floating potential. Furthermore, we directly demonstrate the existence of two regimes, in which parallel currents to the sheath do or do not significantly damp charge separation and thus blob radial velocity.
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Affiliation(s)
- I Furno
- Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne (EPFL), Association EURATOM-Confédération Suisse, Lausanne, Switzerland
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41
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Testa D, Carfantan H, Fasoli A, Goodyear A, King Q, Blanchard P, Klein A, Lavanchy P, Panis T. The JET Alfvén Eigenmode Local Manager for the real-time detection and tracking of a frequency-degenerate spectrum of MHD instabilities. Fusion Engineering and Design 2011. [DOI: 10.1016/j.fusengdes.2011.03.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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42
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Theiler C, Furno I, Kuenlin A, Marmillod P, Fasoli A. Practical solutions for reliable triple probe measurements in magnetized plasmas. Rev Sci Instrum 2011; 82:013504. [PMID: 21280828 DOI: 10.1063/1.3516045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The triple probe method to obtain local, time-resolved measurements of density, electron temperature and plasma potential is investigated in detail. The difficulties in obtaining reliable measurements with this technique are discussed and overcome. These include phase delay errors, ion sheath expansion and limited bandwidth due to stray capacitance to ground. In particular, a relatively simple electronic circuit is described to strongly reduce stray capacitance. Measurements with the triple probe are presented in a plasma characterized by interchange-driven turbulence in the TORPEX device. The measured time-averaged and time-dependent, conditionally averaged parameters are cross-checked with other Langmuir probe based techniques, and show good agreement. Triple probe measurements show that electron temperature fluctuations are sufficiently large, such that the identification of plasma potential fluctuations with fluctuations of the floating potential is not a good approximation. Over a large radial region, the time-averaged fluctuation-induced particle flux can, however, be deduced from floating potential only. This is because the phase shift between density and electron temperature is close to zero there and temperature fluctuations do not give rise to a net radial particle transport.
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Affiliation(s)
- C Theiler
- Centre de Recherches en Physique des Plasmas-Ecole Polytechnique Fédérale de Lausanne, Association EURATOM-Confédération Suisse, Switzerland.
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Theiler C, Furno I, Ricci P, Fasoli A, Labit B, Müller SH, Plyushchev G. Cross-field motion of plasma blobs in an open magnetic field line configuration. Phys Rev Lett 2009; 103:065001. [PMID: 19792574 DOI: 10.1103/physrevlett.103.065001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Indexed: 05/28/2023]
Abstract
The radial propagation of blobs generated from plasma instabilities is investigated in an open magnetic field line configuration. Blob cross-field velocities and sizes are obtained from internal probe measurements using pattern recognition. By varying the ion mass, the normalized vertical blob scale a[over] is scanned from a[over] < 1 to a[over] > 1. An analytical expression for the blob velocity including cross-field ion polarization currents, parallel currents to the sheath, and ion-neutral collisions is derived and shows good quantitative agreement with the experimental data. In agreement with previous theoretical studies, this scaling shows that, for a[over] < 1, the blob velocity is limited by cross-field ion polarization currents, while for a[over] > 1 it is limited by parallel currents to the sheath.
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Affiliation(s)
- C Theiler
- Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne (EPFL), Association EURATOM-Confédération Suisse, CH-1015 Lausanne, Switzerland
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Affiliation(s)
- A Fasoli
- Department of Interdisciplinary Endoscopy, National Institute for Cancer Research, Genova, Italy
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Fasoli A, Pugliese V, Furnari M, Gatteschi B, Truini M, Meroni E. Signet ring cell carcinoma of the stomach: correlation between endocytoscopy and histology. Endoscopy 2009; 41 Suppl 2:E65-6. [PMID: 19319785 DOI: 10.1055/s-0028-1119475] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- A Fasoli
- Division of Interdisciplinary Endoscopy, National Institute for Cancer Research, Genoa, Italy
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Poli FM, Podestà M, Fasoli A. A robust method for measurement of fluctuation parallel wavenumber in laboratory plasmas. Rev Sci Instrum 2009; 80:053501. [PMID: 19485502 DOI: 10.1063/1.3125627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Measuring the parallel wavenumber is fundamental for the experimental characterization of electrostatic instabilities. It becomes particularly important in toroidal geometry, where spatial inhomogeneities and curvature can excite both drift instabilities, whose wavenumber parallel to the magnetic field is finite, and interchange instabilities, which typically have vanishing parallel wavenumber. We demonstrate that multipoint measurements can provide a robust method for the discrimination between the two cases.
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Affiliation(s)
- F M Poli
- CRPP-EPFL, Association EURATOM-Confédération Suisse, Lausanne 1015, Switzerland.
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Casiraghi C, Hartschuh A, Qian H, Piscanec S, Georgi C, Fasoli A, Novoselov KS, Basko DM, Ferrari AC. Raman spectroscopy of graphene edges. Nano Lett 2009; 9:1433-41. [PMID: 19290608 DOI: 10.1021/nl8032697] [Citation(s) in RCA: 379] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Graphene edges are of particular interest since their orientation determines the electronic properties. Here we present a detailed Raman investigation of graphene flakes with edges oriented at different crystallographic directions. We also develop a real space theory for Raman scattering to analyze the general case of disordered edges. The position, width, and intensity of G and D peaks are studied as a function of the incident light polarization. The D-band is strongest for polarization parallel to the edge and minimum for perpendicular. Raman mapping shows that the D peak is localized in proximity of the edge. For ideal edges, the D peak is zero for zigzag orientation and large for armchair, allowing in principle the use of Raman spectroscopy as a sensitive tool for edge orientation. However, for real samples, the D to G ratio does not always show a significant dependence on edge orientation. Thus, even though edges can appear macroscopically smooth and oriented at well-defined angles, they are not necessarily microscopically ordered.
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Affiliation(s)
- C Casiraghi
- Engineering Department, Cambridge University, Cambridge, UK
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Abstract
Fast framing cameras constitute an important recent diagnostic development aimed at monitoring light emission from magnetically confined plasmas, and are now commonly used to study turbulence in plasmas. In the TORPEX toroidal device [A. Fasoli et al., Phys. Plasmas 13, 055902 (2006)], low frequency electrostatic fluctuations associated with drift-interchange waves are routinely measured by means of extensive sets of Langmuir probes. A Photron Ultima APX-RS fast framing camera has recently been acquired to complement Langmuir probe measurements, which allows comparing statistical and spectral properties of visible light and electrostatic fluctuations. A direct imaging system has been developed, which allows viewing the light, emitted from microwave-produced plasmas tangentially and perpendicularly to the toroidal direction. The comparison of the probability density function, power spectral density, and autoconditional average of the camera data to those obtained using a multiple head electrostatic probe covering the plasma cross section shows reasonable agreement in the case of perpendicular view and in the plasma region where interchange modes dominate.
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Affiliation(s)
- D Iraji
- Ecole Polytechnique Federale de Lausanne, Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne, Switzerland.
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Diallo A, Fasoli A, Furno I, Labit B, Podestà M, Theiler C. Dynamics of plasma blobs in a shear flow. Phys Rev Lett 2008; 101:115005. [PMID: 18851292 DOI: 10.1103/physrevlett.101.115005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Indexed: 05/26/2023]
Abstract
The global dynamic of plasma blobs in a shear flow is investigated in a simple magnetized torus using the spatial Fourier harmonics (k-space) framework. Direct experimental evidence of a linear drift in k space of the density fluctuation energy synchronized with blob events is presented. During this drift, an increase of the fluctuation energy and a production of the kinetic energy associated with blobs are observed. The energy source of the blob is analyzed using an advection-dissipation-type equation that includes blob-flow exchange energy, linear drift in k space, nonlinear processes, and viscous dissipations. We show that blobs tap their energy from the dominant ExB vertical background flow during the linear drift stage. The exchange of energy is unidirectional as there is no evidence that blobs return energy to the flow.
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Affiliation(s)
- A Diallo
- Centre de Recherches en Physique des Plasmas Association Euratom-Confédération Suisse, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland.
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Labit B, Furno I, Podestà M, Fasoli A. Two-dimensional time resolved measurements of toroidal velocity correlated with density blobs in magnetized plasmas. Rev Sci Instrum 2008; 79:086104. [PMID: 19044385 DOI: 10.1063/1.2965141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A new method for toroidal velocity measurements with Mach probes is presented. This technique is based on the conditional sampling technique, the triggering events being density blobs. A reconstruction of the time resolved two-dimensional profile of electron density, electron temperature, plasma potential, and toroidal velocity is possible with a single point measurement on a shot-to-shot basis.
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Affiliation(s)
- B Labit
- Centre de Recherches en Physique des Plasmas (CRPP), Ecole Polytechnique Federale de Lausanne (EPFL), Association Euratom-Confederation Helvetique, CH-1015 Lausanne, Switzerland
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