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Alharbi A, Schiesko L, Minea T. Ion-acoustic waves in weakly ionized plasmas with charge-exchange collisions. Sci Rep 2023; 13:14121. [PMID: 37644070 PMCID: PMC10465566 DOI: 10.1038/s41598-023-39780-5] [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] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/31/2023] [Indexed: 08/31/2023] Open
Abstract
Ion-neutral charge-exchange collisions in plasmas of laboratory, space, and astrophysical origins are fundamental to understanding wave dissipation and wave generation phenomena. This paper implements a charge-exchange collision operator in the Boltzmann-Poisson system equations for a weakly ionized plasma. When considering an electric field perturbation, the governing kinetic equations provide significant results concerning the plasma conductivity and the dielectric function, appearing in simple, sensible forms. The present analysis reveals a backward wave propagation phenomenon at maximum conductivity when the wavenumber of the plasma wave is smaller than the reciprocal of the ion-neutral collisions mean free path. In addition, it is shown that ion-neutral coupling resulting from charge-exchange collisions enhances ion-acoustic waves below and beyond the ion plasma frequency and leads to the onset of a fundamental instability that overcomes Landau damping under certain circumstances. The collisionless model is recovered as a limiting case, i.e., in the asymptotic limit of a long mean free path.
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Affiliation(s)
- Abdulrahman Alharbi
- King Abdulaziz City for Science and Technology (KACST), 11442, Riyadh, Saudi Arabia.
- Laboratoire de Physique des Gaz et des Plasmas, CNRS, Université Paris-Saclay, 91405, Orsay, France.
| | - L Schiesko
- CEA, IRFM, 13108, Saint-Paul-lez-Durance, France
| | - T Minea
- Laboratoire de Physique des Gaz et des Plasmas, CNRS, Université Paris-Saclay, 91405, Orsay, France
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Wimmer C, Bonomo F, Hurlbatt A, Schiesko L, Fantz U, Harder ND, Heinemann B, Mimo A, Orozco G, Agostini M, Barbisan M, Brombin M, Delogu R, Pimazzoni A, Poggi C, Serianni G, Ugoletti M, Veltri P. Beamlet scraping and its influence on the beam divergence at the BATMAN Upgrade test facility. Rev Sci Instrum 2020; 91:013509. [PMID: 32012577 DOI: 10.1063/1.5129336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
For the ITER fusion experiment, two neutral beam injectors are required for plasma heating and current drive. Each injector supplies a power of about 17 MW, obtained from neutralization of 40 A (46 A), 1 MeV (0.87 MeV) negative deuterium (hydrogen) ions. The full beam is composed of 1280 beamlets, formed in 16 beamlet groups, and strict requirements apply to the beamlet core divergence (<7 mrad). The test facility BATMAN Upgrade uses an ITER-like grid with one beamlet group, which consists of 70 apertures. In a joint campaign performed by IPP and Consorzio RFX to better assess the beam optics, the divergence of a single beamlet was compared to a group of beamlets at BATMAN Upgrade. The single beamlet is measured with a carbon fiber composite tile calorimeter and by beam emission spectroscopy, whereas the divergence of the group of beamlets is measured by beam emission spectroscopy only. When increasing the RF power at low extraction voltages, the divergence of the beamlet and of the group of beamlets is continuously decreasing and no inflection point toward an overperveant beam is found. At the same time, scraping of the extracted ion beam at the second grid (extraction grid) takes place at higher RF power, supported by the absence of the normally seen linear behavior between the measured negative ion density in the plasma close to the extraction system and the measured extracted ion current. Beside its influence on the divergence, beamlet scraping needs to be considered for the determination of the correct perveance and contributes to the measured coextracted electron current.
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Affiliation(s)
- C Wimmer
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - F Bonomo
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - A Hurlbatt
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - L Schiesko
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - U Fantz
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - N den Harder
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - B Heinemann
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - A Mimo
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - G Orozco
- Max-Planck-Institut für Plasmaphysik (IPP), Boltzmannstr. 2, 85748 Garching, Germany
| | - M Agostini
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Barbisan
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Brombin
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - R Delogu
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - A Pimazzoni
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - C Poggi
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - G Serianni
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Ugoletti
- Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy
| | - P Veltri
- ITER Organization, Route de Vinon sur Verdon, CS 90 046, 13067 St. Paul-lez-Durance, France
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Agostinetti P, Giacomin M, Serianni G, Veltri P, Bonomo F, Schiesko L. Preliminary results concerning the simulation of beam profiles from extracted ion current distributions for mini-STRIKE. Rev Sci Instrum 2016; 87:02B913. [PMID: 26932085 DOI: 10.1063/1.4933185] [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: 06/05/2023]
Abstract
The Radio Frequency (RF) negative hydrogen ion source prototype has been chosen for the ITER neutral beam injectors due to its optimal performances and easier maintenance demonstrated at Max-Planck-Institut für Plasmaphysik, Garching in hydrogen and deuterium. One of the key information to better understand the operating behavior of the RF ion sources is the extracted negative ion current density distribution. This distribution-influenced by several factors like source geometry, particle drifts inside the source, cesium distribution, and layout of cesium ovens-is not straightforward to be evaluated. The main outcome of the present contribution is the development of a minimization method to estimate the extracted current distribution using the footprint of the beam recorded with mini-STRIKE (Short-Time Retractable Instrumented Kalorimeter). To accomplish this, a series of four computational models have been set up, where the output of a model is the input of the following one. These models compute the optics of the ion beam, evaluate the distribution of the heat deposited on the mini-STRIKE diagnostic calorimeter, and finally give an estimate of the temperature distribution on the back of mini-STRIKE. Several iterations with different extracted current profiles are necessary to give an estimate of the profile most compatible with the experimental data. A first test of the application of the method to the BAvarian Test Machine for Negative ions beam is given.
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Affiliation(s)
- P Agostinetti
- Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Giacomin
- Physics Department, Università di Padova, via F. Marzolo 8, 35131 Padova, Italy
| | - G Serianni
- Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova, Italy
| | - P Veltri
- Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova, Italy
| | - F Bonomo
- Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching, Germany
| | - L Schiesko
- Max-Planck-Institut für Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching, Germany
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Wimmer C, Schiesko L, Fantz U. Investigation of the boundary layer during the transition from volume to surface dominated H⁻ production at the BATMAN test facility. Rev Sci Instrum 2016; 87:02B310. [PMID: 26932038 DOI: 10.1063/1.4932985] [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] [Indexed: 06/05/2023]
Abstract
BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 18 scale H(-) source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H(-) production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H(-) density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H(-) density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (j(H(-)), j(e)) exists with the Cs emission.
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Affiliation(s)
- C Wimmer
- Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching, Germany
| | - L Schiesko
- Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching, Germany
| | - U Fantz
- Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching, Germany
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Brombin M, Spolaore M, Serianni G, Pomaro N, Taliercio C, Dalla Palma M, Pasqualotto R, Schiesko L. Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from Radio Frequency plasma) experiment: tests in BATMAN (BAvarian Test Machine for Negative ions). Rev Sci Instrum 2014; 85:11D832. [PMID: 25430245 DOI: 10.1063/1.4890601] [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] [Indexed: 06/04/2023]
Abstract
A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors' holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns.
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Affiliation(s)
- M Brombin
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - M Spolaore
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - G Serianni
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - N Pomaro
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - C Taliercio
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - M Dalla Palma
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - R Pasqualotto
- Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - L Schiesko
- Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching, Germany
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Serianni G, De Muri M, Muraro A, Veltri P, Bonomo F, Chitarin G, Pasqualotto R, Pavei M, Rizzolo A, Valente M, Franzen P, Ruf B, Schiesko L. First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE). Rev Sci Instrum 2014; 85:02A736. [PMID: 24593470 DOI: 10.1063/1.4861391] [Citation(s) in RCA: 4] [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: 06/03/2023]
Abstract
The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions.
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Affiliation(s)
- G Serianni
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M De Muri
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - A Muraro
- Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milano, Italy
| | - P Veltri
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - F Bonomo
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - G Chitarin
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - R Pasqualotto
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Pavei
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - A Rizzolo
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - M Valente
- Consorzio RFX, Euratom-ENEA association, Corso Stati Uniti 4, 35127 Padova, Italy
| | - P Franzen
- Max-Planck-Institut für Plasmaphysik, D-85748 Garching bei München, Germany
| | - B Ruf
- Max-Planck-Institut für Plasmaphysik, D-85748 Garching bei München, Germany
| | - L Schiesko
- Max-Planck-Institut für Plasmaphysik, D-85748 Garching bei München, Germany
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Brombin M, Spolaore M, Serianni G, Barzon A, Franchin L, Pasqualotto R, Pomaro N, Schiesko L, Taliercio C, Trevisan L. Electrostatic sensors for SPIDER experiment: design, manufacture of prototypes, and first tests. Rev Sci Instrum 2014; 85:02A715. [PMID: 24593449 DOI: 10.1063/1.4831746] [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] [Indexed: 06/03/2023]
Abstract
A system of electrostatic sensors has been designed for the SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) experiment, prototype RF source of the ITER NBI (neutral beam injection). A prototype of the sensor system was manufactured and tested at the BATMAN (BAvarian Test MAchine for Negative ions) facility, where the plasma environment is similar to that of SPIDER. Different aspects concerning the mechanical manufacturing and the signal conditioning are presented, among them the RF compensation adopted to reduce the RF effects which could lead to overestimated values of the electron temperature. The first commissioning tests provided ion saturation current values in the range assumed for the design, so the deduced plasma density estimate is consistent with the expected values.
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Affiliation(s)
- M Brombin
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - M Spolaore
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - G Serianni
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - A Barzon
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - L Franchin
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - R Pasqualotto
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - N Pomaro
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - L Schiesko
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, 1533, D-85740 Garching, Germany
| | - C Taliercio
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
| | - L Trevisan
- Consorzio RFX, Associazione Euratom-Enea sulla Fusione, Corso Stati Uniti 4, I-35127 Padova, Italy
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Heinemann B, Fantz U, Franzen P, Froeschle M, Kircher M, Kraus W, Martens C, Nocentini R, Riedl R, Ruf B, Schiesko L, Wimmer C, Wuenderlich D. Negative ion test facility ELISE—Status and first results. Fusion Engineering and Design 2013. [DOI: 10.1016/j.fusengdes.2012.11.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
It has been observed that there are differences between the uncompensated Langmuir probes installed in the upper and lower areas of the rf driven H(-) sources at IPP Garching. The two probes often had substantially different floating potentials or ion saturation currents. In an effort to understand the reasons for these differences a Langmuir probe analysis system was used on the probes to collect the full current voltage characteristic. The results show what is likely the formation of an ion-ion plasma. The paper shows the effect of beam extraction and the presence of caesium on the probe characteristics.
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Affiliation(s)
- P McNeely
- Max Planck Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching, Germany.
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