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Afshari M, Morris S, Geulig LD, Chitgar ZM, Gibbon P, Thirolf PG, Schreiber J. The role of collisional ionization in heavy ion acceleration by high intensity laser pulses. Sci Rep 2022; 12:18260. [PMID: 36309599 PMCID: PMC9617862 DOI: 10.1038/s41598-022-23148-2] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/25/2022] [Indexed: 12/31/2022] Open
Abstract
We present here simulation results of the laser-driven acceleration of gold ions using the EPOCH code. Recently, an experiment reported the acceleration of gold ions up to 7 MeV/nucleon with a strong dependency of the charge-state distribution on target thickness and the detection of the highest charge states [Formula: see text]. Our simulations using a developmental branch of EPOCH (4.18-Ionization) show that collisional ionization is the most important cause of charge states beyond Z = 51 up to He-like Au.
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Affiliation(s)
- M. Afshari
- grid.5252.00000 0004 1936 973XFakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching bei München, Germany
| | - S. Morris
- grid.7372.10000 0000 8809 1613Department of Physics, University of Warwick, Coventry, CV4 7AL UK
| | - L. D. Geulig
- grid.5252.00000 0004 1936 973XFakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching bei München, Germany
| | - Z. M. Chitgar
- grid.8385.60000 0001 2297 375XInstitute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - P. Gibbon
- grid.8385.60000 0001 2297 375XInstitute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany ,grid.5596.f0000 0001 0668 7884Centre for Mathematical Plasma Astrophysics, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - P. G. Thirolf
- grid.5252.00000 0004 1936 973XFakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching bei München, Germany
| | - J. Schreiber
- grid.5252.00000 0004 1936 973XFakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching bei München, Germany
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2
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Lindner FH, Fitzpatrick EG, Haffa D, Ponnath L, Schmidt AK, Speicher M, Zielbauer B, Schreiber J, Thirolf PG. Charge-state resolved laser acceleration of gold ions to beyond 7 MeV/u. Sci Rep 2022; 12:4784. [PMID: 35315434 PMCID: PMC8938412 DOI: 10.1038/s41598-022-08556-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/08/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractIn the past years, the interest in the laser-driven acceleration of heavy ions in the mass range of $$\text {A}\approx 200$$
A
≈
200
has been increasing due to promising application ideas like the fission-fusion nuclear reaction mechanism, aiming at the production of neutron-rich isotopes relevant for the astrophysical r-process nucleosynthesis. In this paper, we report on the laser acceleration of gold ions to beyond 7 MeV/u, exceeding for the first time an important prerequisite for this nuclear reaction scheme. Moreover, the gold ion charge states have been detected with an unprecedented resolution, which enables the separation of individual charge states up to 4 MeV/u. The recorded charge-state distributions show a remarkable dependency on the target foil thickness and differ from simulations, lacking a straight-forward explanation by the established ionization models.
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Kawula M, Binder TM, Liprandi S, Viegas R, Parodi K, Thirolf PG. Sub-millimeter precise photon interaction position determination in large monolithic scintillators via convolutional neural network algorithms. Phys Med Biol 2021; 66. [PMID: 34062523 DOI: 10.1088/1361-6560/ac06e2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 02/21/2021] [Accepted: 06/01/2021] [Indexed: 11/11/2022]
Abstract
In this work, we present the development and application of a convolutional neural network (CNN)-based algorithm to precisely determine the interaction position ofγ-quanta in large monolithic scintillators. Those are used as an absorber component of a Compton camera (CC) system under development for ion beam range verification via prompt-gamma imaging. We examined two scintillation crystals: LaBr3:Ce and CeBr3. Each crystal had dimensions of 50.8 mm × 50.8 mm × 30 mm and was coupled to a 64-fold segmented multi-anode photomultiplier tube (PMT) with an 8 × 8 pixel arrangement. We determined the spatial resolution for three photon energies of 662, 1.17 and 1.33 MeV obtained from 2D detector scans with tightly collimated137Cs and60Co photon sources. With the new algorithm we achieved a spatial resolution for the CeBr3 crystal below 1.11(8) mm and below 0.98(7) mm for the LaBr3:Ce detector for all investigated energies between 662 keV and 1.33 MeV. We thereby improved the performance by more than a factor of 2.5 compared to the previously used categorical average pattern algorithm, which is a variation of the well-established k-nearest neighbor algorithm. The trained CNN has a low memory footprint and enables the reconstruction of up to 104events per second with only one GPU. Those improvements are crucial on the way to future clinicalin vivoapplicability of the CC for ion beam range verification.
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Affiliation(s)
- M Kawula
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany
| | - T M Binder
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany.,KETEK GmbH, Munich, Germany
| | - S Liprandi
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany
| | - R Viegas
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany.,University of Coimbra, Portugal
| | - K Parodi
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany
| | - P G Thirolf
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Garching b. München, Germany
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4
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Lindner FH, Bin JH, Englbrecht F, Haffa D, Bolton PR, Gao Y, Hartmann J, Hilz P, Kreuzer C, Ostermayr TM, Rösch TF, Speicher M, Parodi K, Thirolf PG, Schreiber J. A novel approach to electron data background treatment in an online wide-angle spectrometer for laser-accelerated ion and electron bunches. Rev Sci Instrum 2018; 89:013301. [PMID: 29390656 DOI: 10.1063/1.5001990] [Citation(s) in RCA: 3] [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] [Indexed: 06/07/2023]
Abstract
Laser-based ion acceleration is driven by electrical fields emerging when target electrons absorb laser energy and consecutively leave the target material. A direct correlation between these electrons and the accelerated ions is thus to be expected and predicted by theoretical models. We report on a modified wide-angle spectrometer, allowing the simultaneous characterization of angularly resolved energy distributions of both ions and electrons. Equipped with online pixel detectors, the RadEye1 detectors, the investigation of this correlation gets attainable on a single shot basis. In addition to first insights, we present a novel approach for reliably extracting the primary electron energy distribution from the interfering secondary radiation background. This proves vitally important for quantitative extraction of average electron energies (temperatures) and emitted total charge.
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Affiliation(s)
- F H Lindner
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - J H Bin
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - F Englbrecht
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - D Haffa
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - P R Bolton
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - Y Gao
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - J Hartmann
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - P Hilz
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - C Kreuzer
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - T M Ostermayr
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - T F Rösch
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - M Speicher
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - K Parodi
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - P G Thirolf
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
| | - J Schreiber
- Lehrstuhl für Experimentalphysik - Medizinische Physik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching bei München, Germany
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5
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Assmann W, Kellnberger S, Reinhardt S, Lehrack S, Edlich A, Thirolf PG, Moser M, Dollinger G, Omar M, Ntziachristos V, Parodi K. Ionoacoustic characterization of the proton Bragg peak with submillimeter accuracy. Med Phys 2015; 42:567-74. [PMID: 25652477 DOI: 10.1118/1.4905047] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
PURPOSE Range verification in ion beam therapy relies to date on nuclear imaging techniques which require complex and costly detector systems. A different approach is the detection of thermoacoustic signals that are generated due to localized energy loss of ion beams in tissue (ionoacoustics). Aim of this work was to study experimentally the achievable position resolution of ionoacoustics under idealized conditions using high frequency ultrasonic transducers and a specifically selected probing beam. METHODS A water phantom was irradiated by a pulsed 20 MeV proton beam with varying pulse intensity and length. The acoustic signal of single proton pulses was measured by different PZT-based ultrasound detectors (3.5 and 10 MHz central frequencies). The proton dose distribution in water was calculated by Geant4 and used as input for simulation of the generated acoustic wave by the matlab toolbox k-WAVE. RESULTS In measurements from this study, a clear signal of the Bragg peak was observed for an energy deposition as low as 10(12) eV. The signal amplitude showed a linear increase with particle number per pulse and thus, dose. Bragg peak position measurements were reproducible within ±30 μm and agreed with Geant4 simulations to better than 100 μm. The ionoacoustic signal pattern allowed for a detailed analysis of the Bragg peak and could be well reproduced by k-WAVE simulations. CONCLUSIONS The authors have studied the ionoacoustic signal of the Bragg peak in experiments using a 20 MeV proton beam with its correspondingly localized energy deposition, demonstrating submillimeter position resolution and providing a deep insight in the correlation between the acoustic signal and Bragg peak shape. These results, together with earlier experiments and new simulations (including the results in this study) at higher energies, suggest ionoacoustics as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound imaging. This acoustic range verification approach could offer the possibility of combining anatomical ultrasound and Bragg peak imaging, but further studies are required for translation of these findings to clinical application.
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Affiliation(s)
- W Assmann
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
| | - S Kellnberger
- Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764, Germany
| | - S Reinhardt
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
| | - S Lehrack
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
| | - A Edlich
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
| | - P G Thirolf
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
| | - M Moser
- Institute for Applied Physics and Measurement Technology, Universität der Bundeswehr, Werner-Heisenberg-Weg 39, Neubiberg 85577, Germany
| | - G Dollinger
- Institute for Applied Physics and Measurement Technology, Universität der Bundeswehr, Werner-Heisenberg-Weg 39, Neubiberg 85577, Germany
| | - M Omar
- Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764, Germany
| | - V Ntziachristos
- Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764, Germany
| | - K Parodi
- Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
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6
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Thirolf PG, Aldawood S, Boehmer M, Bortfeldt J, Castelhano I, Gernhaeuser R, v.d. Kolff H, Lang C, Maier L, Schaart DR, Parodi K. SU-E-J-46: Development of a Compton Camera Prototype for Online Range Verification of Laser-Accelerated Proton Beams. Med Phys 2014. [DOI: 10.1118/1.4888098] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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7
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Minaya Ramirez E, Ackermann D, Blaum K, Block M, Droese C, Düllmann CE, Dworschak M, Eibach M, Eliseev S, Haettner E, Herfurth F, Heßberger FP, Hofmann S, Ketelaer J, Marx G, Mazzocco M, Nesterenko D, Novikov YN, Plaß WR, Rodríguez D, Scheidenberger C, Schweikhard L, Thirolf PG, Weber C. Direct mapping of nuclear shell effects in the heaviest elements. Science 2012; 337:1207-10. [PMID: 22878498 DOI: 10.1126/science.1225636] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Quantum-mechanical shell effects are expected to strongly enhance nuclear binding on an "island of stability" of superheavy elements. The predicted center at proton number Z = 114, 120, or 126 and neutron number N = 184 has been substantiated by the recent synthesis of new elements up to Z = 118. However, the location of the center and the extension of the island of stability remain vague. High-precision mass spectrometry allows the direct measurement of nuclear binding energies and thus the determination of the strength of shell effects. Here, we present such measurements for nobelium and lawrencium isotopes, which also pin down the deformed shell gap at N = 152.
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8
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Haettner E, Ackermann D, Audi G, Blaum K, Block M, Eliseev S, Fleckenstein T, Herfurth F, Hessberger FP, Hofmann S, Ketelaer J, Ketter J, Kluge HJ, Marx G, Mazzocco M, Novikov YN, Plass WR, Rahaman S, Rauscher T, Rodríguez D, Schatz H, Scheidenberger C, Schweikhard L, Sun B, Thirolf PG, Vorobjev G, Wang M, Weber C. Mass measurements of very neutron-deficient Mo and Tc isotopes and their impact on rp process nucleosynthesis. Phys Rev Lett 2011; 106:122501. [PMID: 21517310 DOI: 10.1103/physrevlett.106.122501] [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: 08/26/2010] [Indexed: 05/30/2023]
Abstract
The masses of ten proton-rich nuclides, including the N=Z+1 nuclides ⁸⁵Mo and ⁸⁷Tc, were measured with the Penning trap mass spectrometer SHIPTRAP. Compared to the Atomic Mass Evaluation 2003 a systematic shift of the mass surface by up to 1.6 MeV is observed causing significant abundance changes of the ashes of astrophysical x-ray bursts. Surprisingly low α separation energies for neutron-deficient Mo and Tc are found, making the formation of a ZrNb cycle in the rp process possible. Such a cycle would impose an upper temperature limit for the synthesis of elements beyond Nb in the rp process.
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Affiliation(s)
- E Haettner
- II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen, Germany.
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9
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Wimmer K, Kröll T, Krücken R, Bildstein V, Gernhäuser R, Bastin B, Bree N, Diriken J, Van Duppen P, Huyse M, Patronis N, Vermaelen P, Voulot D, Van de Walle J, Wenander F, Fraile LM, Chapman R, Hadinia B, Orlandi R, Smith JF, Lutter R, Thirolf PG, Labiche M, Blazhev A, Kalkühler M, Reiter P, Seidlitz M, Warr N, Macchiavelli AO, Jeppesen HB, Fiori E, Georgiev G, Schrieder G, Das Gupta S, Lo Bianco G, Nardelli S, Butterworth J, Johansen J, Riisager K. Discovery of the shape coexisting 0+ state in 32 Mg by a two neutron transfer reaction. Phys Rev Lett 2010; 105:252501. [PMID: 21231582 DOI: 10.1103/physrevlett.105.252501] [Citation(s) in RCA: 6] [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] [Received: 08/05/2010] [Indexed: 05/30/2023]
Abstract
The "island of inversion" nucleus 32 Mg has been studied by a (t, p) two neutron transfer reaction in inverse kinematics at REX-ISOLDE. The shape coexistent excited 0+ state in 32 Mg has been identified by the characteristic angular distribution of the protons of the Δ L=0 transfer. The excitation energy of 1058 keV is much lower than predicted by any theoretical model. The low γ-ray intensity observed for the decay of this 0+ state indicates a lifetime of more than 10 ns. Deduced spectroscopic amplitudes are compared with occupation numbers from shell-model calculations.
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Affiliation(s)
- K Wimmer
- Physik Department E12, Technische Universität München, 85748 Garching, Germany
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10
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Block M, Ackermann D, Blaum K, Droese C, Dworschak M, Eliseev S, Fleckenstein T, Haettner E, Herfurth F, Hessberger FP, Hofmann S, Ketelaer J, Ketter J, Kluge HJ, Marx G, Mazzocco M, Novikov YN, Plass WR, Popeko A, Rahaman S, Rodríguez D, Scheidenberger C, Schweikhard L, Thirolf PG, Vorobyev GK, Weber C. Direct mass measurements above uranium bridge the gap to the island of stability. Nature 2010; 463:785-8. [DOI: 10.1038/nature08774] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 12/17/2009] [Indexed: 11/09/2022]
Affiliation(s)
- M Block
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany.
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11
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Schwerdtfeger W, Thirolf PG, Wimmer K, Habs D, Mach H, Rodriguez TR, Bildstein V, Egido JL, Fraile LM, Gernhäuser R, Hertenberger R, Heyde K, Hoff P, Hübel H, Köster U, Kröll T, Krücken R, Lutter R, Morgan T, Ring P. Shape coexistence near neutron number N=20: first identification of the E0 decay from the deformed first excited Jpi=0+ state in 30Mg. Phys Rev Lett 2009; 103:012501. [PMID: 19659139 DOI: 10.1103/physrevlett.103.012501] [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: 08/02/2008] [Revised: 02/20/2009] [Indexed: 05/28/2023]
Abstract
The 1789 keV state in 30Mg was identified as the first excited 0+ state via its electric monopole (E0) transition to the ground state. The measured small value of rho2(E0,0(2)+-->0(1)+)=(26.2+/-7.5)x10(-3) implies within a two-level model a small mixing of competing configurations with largely different intrinsic quadrupole deformation near the neutron shell closure at N=20. Axially symmetric configuration mixing calculations identify the ground state of 30Mg to be based on neutron configurations below the N=20 shell closure, while the excited 0+ state mainly consists of two neutrons excited into the nu 1f7/2 orbital. The experimental result represents the first case where an E0 back decay from a strongly deformed second to the normal deformed first nuclear potential minimum well has been unambiguously identified, thus directly proving shape coexistence at the borderline of the much-debated "island of inversion."
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Affiliation(s)
- W Schwerdtfeger
- Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
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12
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Rauth C, Ackermann D, Blaum K, Block M, Chaudhuri A, Di Z, Eliseev S, Ferrer R, Habs D, Herfurth F, Hessberger FP, Hofmann S, Kluge HJ, Maero G, Martín A, Marx G, Mukherjee M, Neumayr JB, Plass WR, Rahaman S, Rodríguez D, Scheidenberger C, Schweikhard L, Thirolf PG, Vorobjev G, Weber C. First Penning trap mass measurements beyond the proton drip line. Phys Rev Lett 2008; 100:012501. [PMID: 18232754 DOI: 10.1103/physrevlett.100.012501] [Citation(s) in RCA: 2] [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: 10/26/2006] [Revised: 07/19/2007] [Indexed: 05/25/2023]
Abstract
The masses of six neutron-deficient rare holmium and thulium isotopes close to the proton drip line were determined with the SHIPTRAP Penning trap mass spectrometer. For the first time the masses of the proton-unbound isotopes 144,145Ho and 147,148Tm were directly measured. The proton separation energies were derived from the measured mass values and compared to predictions from mass formulas. The new values of the proton separation energies are used to determine the location of the proton drip line for holmium and thulium more accurately.
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Affiliation(s)
- C Rauth
- Gesellschaft für Schwerionenforschung (GSI), Planckstrasse 1, 64291 Darmstadt, Germany
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13
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Wilson AN, Singh AK, Hübel H, Davidson PM, Görgen A, Rossbach D, Korichi A, Astier A, Azaiez F, Bazzacco D, Bourgeois C, Buforn N, Byrne AP, Dracoulis GD, Hannachi F, Hauschild K, Korten W, Kröll T, Lane GJ, Lopez-Martens A, Redon N, Reiter P, Rossi-Alvarez C, Schonwasser G, Stezowski O, Thirolf PG. Excitation energies of superdeformed States in 196Pb: towards a systematic study of the second well in Pb isotopes. Phys Rev Lett 2005; 95:182501. [PMID: 16383897 DOI: 10.1103/physrevlett.95.182501] [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: 05/06/2005] [Indexed: 05/05/2023]
Abstract
The excitation energy of the lowest-energy superdeformed band in 196Pb is established using the techniques of time-correlated gamma-ray spectroscopy. Together with previous measurements on 192Pb and 194Pb, this result allows superdeformed excitation energies, binding energies, and two-proton and two-neutron separation energies to be studied systematically, providing stringent tests for current nuclear models. The results are examined for evidence of a "superdeformed shell gap."
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Affiliation(s)
- A N Wilson
- Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia.
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Niedermaier O, Scheit H, Bildstein V, Boie H, Fitting J, von Hahn R, Köck F, Lauer M, Pal UK, Podlech H, Repnow R, Schwalm D, Alvarez C, Ames F, Bollen G, Emhofer S, Habs D, Kester O, Lutter R, Rudolph K, Pasini M, Thirolf PG, Wolf BH, Eberth J, Gersch G, Hess H, Reiter P, Thelen O, Warr N, Weisshaar D, Aksouh F, Van den Bergh P, Van Duppen P, Huyse M, Ivanov O, Mayet P, Van de Walle J, Aystö J, Butler PA, Cederkäll J, Delahaye P, Fynbo HOU, Fraile LM, Forstner O, Franchoo S, Köster U, Nilsson T, Oinonen M, Sieber T, Wenander F, Pantea M, Richter A, Schrieder G, Simon H, Behrens T, Gernhäuser R, Kröll T, Krücken R, Münch M, Davinson T, Gerl J, Huber G, Hurst A, Iwanicki J, Jonson B, Lieb P, Liljeby L, Schempp A, Scherillo A, Schmidt P, Walter G. "Safe" Coulomb excitation of 30Mg. Phys Rev Lett 2005; 94:172501. [PMID: 15904283 DOI: 10.1103/physrevlett.94.172501] [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: 12/17/2004] [Indexed: 05/02/2023]
Abstract
We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient gamma spectrometer MINIBALL. Using 30Mg ions accelerated to an energy of 2.25 MeV/u together with a thin (nat)Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation gamma-ray yields the B(E2;0(+)gs-->2(+)1) value of 30Mg was determined to be 241(31)e2 fm4. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope 30Mg resides outside the "island of inversion."
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Affiliation(s)
- O Niedermaier
- Max-Planck-Insitut für Kernphysik, Heidelberg, Germany
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Thirolf PG, van der Werf SY, Ott J, Máté Z, Gulyás J, Csatlós M, Hunyadi M, Krasznahorkay A, Faestermann T, Metz A, Maier HJ, Hertenberger R, Graw G, Eisermann Y, Habs D, Gassmann D. Hyperdeformation and Clusterization in the Actinide Region. ACTA ACUST UNITED AC 2001. [DOI: 10.1556/aph.13.2001.1-3.12] [Citation(s) in RCA: 6] [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: 11/19/2022]
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