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Yu EP, Awe TJ, Cochrane KR, Peterson KJ, Yates KC, Hutchinson TM, Hatch MW, Bauer BS, Tomlinson K, Sinars DB. Seeding the Electrothermal Instability through a Three-Dimensional, Nonlinear Perturbation. PHYSICAL REVIEW LETTERS 2023; 130:255101. [PMID: 37418744 DOI: 10.1103/physrevlett.130.255101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/24/2023] [Accepted: 05/17/2023] [Indexed: 07/09/2023]
Abstract
Electrothermal instability plays an important role in applications of current-driven metal, creating striations (which seed the magneto-Rayleigh-Taylor instability) and filaments (which provide a more rapid path to plasma formation). However, the initial formation of both structures is not well understood. Simulations show for the first time how a commonly occurring isolated defect transforms into the larger striation and filament, through a feedback loop connecting current and electrical conductivity. Simulations have been experimentally validated using defect-driven self-emission patterns.
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Affiliation(s)
- E P Yu
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - T J Awe
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - K R Cochrane
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - K J Peterson
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - K C Yates
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T M Hutchinson
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M W Hatch
- University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - B S Bauer
- University of Nevada, Reno, Reno, Nevada 89506, USA
| | - K Tomlinson
- General Atomics, San Diego, California 92121, USA
| | - D B Sinars
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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Stollberg C, Kroupp E, Mikitchuk D, Sharma P, Bernshtam V, Cvejić M, Doron R, Stambulchik E, Maron Y, Fruchtman A, Ochs IE, Fisch NJ, Shumlak U. Observation of Fast Current Redistribution in an Imploding Plasma Column. PHYSICAL REVIEW LETTERS 2023; 130:205101. [PMID: 37267532 DOI: 10.1103/physrevlett.130.205101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/10/2023] [Accepted: 05/03/2023] [Indexed: 06/04/2023]
Abstract
Spectroscopic measurements of the magnetic field evolution in a Z-pinch throughout stagnation and with particularly high spatial resolution reveal a sudden current redistribution from the stagnating plasma (SP) to a low-density plasma (LDP) at larger radii, while the SP continues to implode. Based on the plasma parameters it is shown that the current is transferred to an increasing-conductance LDP outside the stagnation, a process likely to be induced by the large impedance of the SP. Since an LDP often exists around imploding plasmas and in various pulsed-power systems, such a fast current redistribution may dramatically affect the behavior and achievable parameters in these systems.
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Affiliation(s)
- C Stollberg
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - E Kroupp
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - D Mikitchuk
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - P Sharma
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - V Bernshtam
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - M Cvejić
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - R Doron
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - E Stambulchik
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - Y Maron
- Weizmann Institute of Science, Herzl Street 243, 7610001 Rehovot, Israel
| | - A Fruchtman
- Department of Physics, Holon Institute of Technology, Holon 58102, Israel
| | - I E Ochs
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540, USA
| | - N J Fisch
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540, USA
| | - U Shumlak
- Aerospace and Energetics Research Program, University of Washington, Seattle, Washington 98195, USA
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3
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Cvejić M, Mikitchuk D, Kroupp E, Doron R, Sharma P, Maron Y, Velikovich AL, Fruchtman A, Ochs IE, Kolmes EJ, Fisch NJ. Self-Generated Plasma Rotation in a Z-Pinch Implosion with Preembedded Axial Magnetic Field. PHYSICAL REVIEW LETTERS 2022; 128:015001. [PMID: 35061496 DOI: 10.1103/physrevlett.128.015001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 10/25/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Using detailed spectroscopic measurements, highly resolved in both time and space, a self-generated plasma rotation is demonstrated using a cylindrical implosion with a preembedded axial magnetic field (B_{z0}). The rotation direction is found to depend on the direction of B_{z0} and its velocity is found comparable to the peak implosion velocity, considerably affecting the force and energy balance throughout the implosion. Moreover, the evolution of the rotation is consistent with magnetic flux surface isorotation, a novel observation in a Z pinch, which is a prototypical time dependent system.
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Affiliation(s)
- M Cvejić
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - D Mikitchuk
- Weizmann Institute of Science, Rehovot 7610001, Israel
- Ecole polytechnique fèdèrale de Lausanne (EPFL), Route Cantonale, 1015 Lausanne, Switzerland
| | - E Kroupp
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - R Doron
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - P Sharma
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Y Maron
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - A L Velikovich
- Plasma Physics Division, Naval Research Laboratory, Washington, D.C. 20375, USA
| | - A Fruchtman
- Holon Institute of Technology, P.O. Box 305, Holon 58102, Israel
| | - I E Ochs
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540, USA
| | - E J Kolmes
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540, USA
| | - N J Fisch
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540, USA
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4
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Narkis J, Conti F, Velikovich AL, Beg FN. Mitigation of magneto-Rayleigh-Taylor instability growth in a triple-nozzle, neutron-producing gas-puff Z pinch. Phys Rev E 2021; 104:L023201. [PMID: 34525596 DOI: 10.1103/physreve.104.l023201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 07/28/2021] [Indexed: 11/07/2022]
Abstract
The gas-puff Z-pinch is a well-known source of x-rays and/or neutrons, but it is highly susceptible to the magneto-Rayleigh-Taylor instability (MRTI). Approaches to MRTI mitigation include density profile tailoring, in which nozzles are added or modified to alter the acceleration trajectory, and axial pre-magnetization, in which perturbations are smoothed out via magnetic field line tension. Here, we present two-dimensional magnetohydrodynamic simulations of loads driven by an 850 kA, 160 ns driver that suggest these mitigation strategies can be additive. The initial axial magnetic field, B_{z0}, to stabilize a 2.5-cm-radius Ne gas liner imploding onto an on-axis deuterium target can be reduced from 0.7 T to 0.3 T by adding a second liner with a radius of 1.25 cm. Because MRTI mitigation tends to increasingly lower yield with higher B_{z0}, the use of a lower field is advantageous. Here, we predict a reduction in yield penalty from >100× with the single liner to <10× with a double liner. A premagnetized, triple nozzle gas puff could therefore be an attractive source for intense neutrons or other fusion applications.
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Affiliation(s)
- J Narkis
- Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA
| | - F Conti
- Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA
| | - A L Velikovich
- Plasma Physics Division, Naval Research Laboratory, Washington, District of Columbia 20375, USA
| | - F N Beg
- Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA
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Aybar N, Dozieres M, Reisman DB, Cvejić M, Mikitchuk D, Conti F, Kroupp E, Doron R, Maron Y, Beg FN. Azimuthal magnetic field distribution in gas-puff Z-pinch implosions with and without external magnetic stabilization. Phys Rev E 2021; 103:053205. [PMID: 34134252 DOI: 10.1103/physreve.103.053205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
An experimental study of the magnetic field distribution in gas-puff Z pinches with and without a preembedded axial magnetic field (B_{z0}) is presented. Spatially resolved, time-gated spectroscopic measurements were made at the Weizmann Institute of Science on a 300 kA, 1.6 μs rise time pulsed-power driver. The radial distribution of the azimuthal magnetic field, B_{θ}, during the implosion, with and without a preembedded axial magnetic field of B_{z0}=0.26T, was measured using Zeeman polarization spectroscopy. The spectroscopic measurements of B_{θ} were consistent with the corresponding values of B_{θ} inferred from current measurements made with a B-dot probe. One-dimensional magnetohydrodynamic simulations, performed with the code trac-ii, showed agreement with the experimentally measured implosion trajectory, and qualitatively reproduced the experimentally measured radial B_{θ} profiles during the implosion when B_{z0}=0.26T was applied. Simulation results of the radial profile of B_{θ} without a preembedded axial magnetic field did not qualitatively match experimental results due to magneto-Rayleigh-Taylor (MRT) instabilities. Our analysis emphasizes the importance of MRT instability mitigation when studying the magnetic field and current distributions in Z pinches. Discrepancies of the simulation results with experiment are discussed.
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Affiliation(s)
- N Aybar
- Center for Energy Research and Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - M Dozieres
- Center for Energy Research and Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - D B Reisman
- Center for Energy Research and Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - M Cvejić
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - D Mikitchuk
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - F Conti
- Center for Energy Research and Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - E Kroupp
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - R Doron
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Y Maron
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - F N Beg
- Center for Energy Research and Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093, USA
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