Effect of insulator surface conditioning on the pinch dynamics and x-ray production of a Ne-filled dense plasma focus

Housley, D.; Hahn, E. N.; Narkis, J.; Angus, J. R.; Link, A. J.; Conti, F.; Beg, F. N.

doi:10.1063/5.0050203

Effect of insulator surface conditioning on the pinch dynamics and x-ray production of a Ne-filled dense plasma focus

Journal Article · Mon Jun 14 00:00:00 EDT 2021 · Journal of Applied Physics

DOI:https://doi.org/10.1063/5.0050203· OSTI ID:1813706

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Univ. of California, San Diego, CA (United States). Center for Energy Research
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

The dense plasma focus (DPF) can be an intense source of x rays, wherein the insulator sleeve strongly dictates the electrical breakdown, which subsequently affects the formation of a plasma sheath and a collapse phase. Experiments on a 25 kJ DPF (operated at 4.4 kJ) are carried out to demonstrate the influence of insulator surface morphology on the pinch structure, dynamics, and x-ray yield using a Ne fill. Two borosilicate insulators are directly compared, one with a smooth finish and the other machined with four circumferential grooves traversing the perimeter of the exterior insulator surface. Comparisons are made through same-shot imaging diagnostics of the evolving plasma sheath during breakdown, rundown, and at the pinch in addition to the time-resolved measurements of emitted x rays via filtered photodiodes. The presence of structures on the insulator sleeve reduces x-ray production across all fill pressures by a factor of 2.8 ± 2.4 on average and reduces the highest x ray producing shots by a factor of 5. ± 1.8. Observations of sheath asymmetry and inhomogeneity at lift-off are observed and correlated with subsequent observations of off-axis radial collapse. Taken together, this suggests that local variations in the insulator surface decrease the spatial uniformity of the sheath, leading to an azimuthally asymmetric focus, reduced electron densities, and, ultimately, degraded x-ray production.

View Accepted Manuscript (DOE)

Research Organization:: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

Sponsoring Organization:: US Air Force Office of Scientific Research; USDOE; USDOE National Nuclear Security Administration (NNSA)

Grant/Contract Number:: AC52-07NA27344

OSTI ID:: 1813706

Alternate ID(s):: OSTI ID: 1787405

Report Number(s):: LLNL-JRNL--819698; 1030634

Journal Information:: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 22 Vol. 129; ISSN 0021-8979

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (40)

NIST Atomic Spectra Database, NIST Standard Reference Database 78 Kramida, Alexander; Ralchenko, Yuri National Institute of Standards and Technology https://doi.org/10.18434/t4w30f	dataset	January 1999
X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E = 50-30,000 eV, Z = 1-92 Henke, B. L.; Gullikson, E. M.; Davis, J. C. Atomic Data and Nuclear Data Tables, Vol. 54, Issue 2, p. 181-342 https://doi.org/10.1006/adnd.1993.1013	journal	July 1993
Plasma Focus Radiative Model: Review of the Lee Model Code Lee, S. Journal of Fusion Energy, Vol. 33, Issue 4 https://doi.org/10.1007/s10894-014-9683-8	journal	March 2014
Laser Shadowgraphic Study of the Influence of Krypton-Seeding, Switch Synchronization and Electrode Geometry on Plasma Dynamic in Plasma Focus Device Talebitaher, A.; Kalaiselvi, S. M. P.; Springham, S. V. Journal of Fusion Energy, Vol. 34, Issue 4 https://doi.org/10.1007/s10894-015-9888-5	journal	February 2015
The dense plasma focus — A high intensity neutron source Bernard, A.; Cloth, P.; Conrads, H. Nuclear Instruments and Methods, Vol. 145, Issue 1 https://doi.org/10.1016/0029-554X(77)90569-9	journal	August 1977
Formation of the plasma layer in a plasma focus device Krompholz, H.; Neff, W.; Rühl, F. Physics Letters A, Vol. 77, Issue 4 https://doi.org/10.1016/0375-9601(80)90657-X	journal	May 1980
The breakdown phase in a coaxial plasma gun Donges, A.; Herziger, G.; Krompholz, H. Physics Letters A, Vol. 76, Issue 5-6 https://doi.org/10.1016/0375-9601(80)90740-9	journal	April 1980
Effect of insulator sleeve contamination on the low energy plasma focus performance Zakaullah, M.; Ahmad, Imtiaz; Murtaza, G. Fusion Engineering and Design, Vol. 23, Issue 4 https://doi.org/10.1016/0920-3796(94)90020-5	journal	January 1994
Optimization of neon soft X-rays emission from 200 J fast miniature dense plasma focus device: A potential source for soft X-ray lithography Kalaiselvi, S. M. P.; Tan, T. L.; Talebitaher, A. Physics Letters A, Vol. 377, Issue 18 https://doi.org/10.1016/j.physleta.2013.03.023	journal	August 2013
Effect of anode shape on pinch structure and X-ray emission of plasma focus device Talukdar, N.; Neog, N. K.; Borthkur, T. K. Results in Physics, Vol. 3 https://doi.org/10.1016/j.rinp.2013.09.001	journal	January 2013
Ionization growth in the breakdown of plasma focus discharge Yordanov, V.; Genov, D.; Ivanova-Stanik, I. Vacuum, Vol. 76, Issue 2-3 https://doi.org/10.1016/j.vacuum.2004.07.071	journal	November 2004
Study of x-ray emission from a table top plasma focus and its application as an x-ray backlighter Beg, F. N.; Ross, I.; Lorenz, A. Journal of Applied Physics, Vol. 88, Issue 6 https://doi.org/10.1063/1.1287220	journal	September 2000
Characteristics of the Dense Plasma Focus Discharge Mather, Joseph W. Physics of Fluids, Vol. 11, Issue 3 https://doi.org/10.1063/1.1691959	journal	January 1968
Faraday cup analysis of ion beams produced by a dense plasma focus Gerdin, G.; Stygar, W.; Venneri, F. Journal of Applied Physics, Vol. 52, Issue 5 https://doi.org/10.1063/1.329145	journal	May 1981
Current distribution during the breakdown in a coaxial electrode system Feugeas, J.; von Pamel, O. Journal of Applied Physics, Vol. 66, Issue 3 https://doi.org/10.1063/1.343444	journal	August 1989
The influence of the insulator surface in the plasma focus behavior Feugeas, J. N. Journal of Applied Physics, Vol. 66, Issue 8 https://doi.org/10.1063/1.344102	journal	October 1989
Effect of insulator sleeve material on the x-ray emission from a plasma focus device Hussain, S.; Shafiq, M.; Badar, M. A. Physics of Plasmas, Vol. 17, Issue 9 https://doi.org/10.1063/1.3484875	journal	September 2010
Electromagnetic particle in cell modeling of the plasma focus: Current sheath formation and lift off Seng, Y. S.; Lee, P.; Rawat, R. S. Physics of Plasmas, Vol. 21, Issue 2 https://doi.org/10.1063/1.4866603	journal	February 2014
Fully kinetic simulations of megajoule-scale dense plasma focus Schmidt, A.; Link, A.; Welch, D. Physics of Plasmas, Vol. 21, Issue 10 https://doi.org/10.1063/1.4897192	journal	October 2014
Development of the dense plasma focus for short-pulse applications Bennett, N.; Blasco, M.; Breeding, K. Physics of Plasmas, Vol. 24, Issue 1 https://doi.org/10.1063/1.4973227	journal	January 2017
One-dimensional theory and simulations of the dynamic Z-pinch Angus, J. R.; Link, A. J.; Schmidt, A. E. W. Physics of Plasmas, Vol. 27, Issue 1 https://doi.org/10.1063/1.5104340	journal	January 2020
Stable current sheath dynamics caused by preionization source in a small plasma focus device using He as an operating gas Khan, H. U.; Hussain, S. S.; Ikram, M. Radiation Effects and Defects in Solids, Vol. 174, Issue 3-4 https://doi.org/10.1080/10420150.2018.1563896	journal	January 2019
E1 Transitions between States with n = 1–6 in Helium‐like Carbon, Nitrogen, Oxygen, Neon, Silicon, and Argon Johnson, W. R.; Savukov, I. M.; Safronova, U. I. The Astrophysical Journal Supplement Series, Vol. 141, Issue 2 https://doi.org/10.1086/340547	journal	August 2002
Effect of electrode surface roughness on breakdown in SF ₆ -N ₂ and SF ₆ -CO ₂ gas mixtures Qiu, Y.; Chalmers, I. D. Journal of Physics D: Applied Physics, Vol. 26, Issue 11 https://doi.org/10.1088/0022-3727/26/11/014	journal	November 1993
The formation of high-density z-pinches Potter, D. Nuclear Fusion, Vol. 18, Issue 6 https://doi.org/10.1088/0029-5515/18/6/008	journal	June 1978
Effect of insulator sleeve material on neutron emission from a plasma focus Beg, F. N.; Zakaullah, M.; Murtaza, G. Physica Scripta, Vol. 46, Issue 2 https://doi.org/10.1088/0031-8949/46/2/008	journal	August 1992
Power limits for dynamical pinch discharges Kies, W. Plasma Physics and Controlled Fusion, Vol. 28, Issue 11 https://doi.org/10.1088/0741-3335/28/11/003	journal	November 1986
Study of neutron emission in a low-energy plasma focus with -source-assisted breakdown Zakaullah, M.; Waheed, A.; Ahmad, Sarfraz Plasma Sources Science and Technology, Vol. 12, Issue 3 https://doi.org/10.1088/0963-0252/12/3/320	journal	June 2003
PIC-MCC method with finite element solver for Poisson equation used in simulation of the breakdown phase in dense plasma focus devices Yordanov, V.; Ivanova-Stanik, I.; Blagoev, A. Journal of Physics: Conference Series, Vol. 44 https://doi.org/10.1088/1742-6596/44/1/031	journal	July 2006
Influence of electrode and insulator materials on the neutron emission in a low energy plasma focus device Rout, R. K.; Garg, A. B.; Shyam, A. IEEE Transactions on Plasma Science, Vol. 23, Issue 6 https://doi.org/10.1109/27.476488	journal	January 1995
Dimensions and lifetime of the plasma focus pinch No authors listed IEEE Transactions on Plasma Science, Vol. 24, Issue 3 https://doi.org/10.1109/27.533118	journal	June 1996
Effect of anode and insulator materials on plasma focus sheath (pinch) current Shyam, A.; Rout, R. K. IEEE Transactions on Plasma Science, Vol. 25, Issue 5 https://doi.org/10.1109/27.649641	journal	January 1997
Effects of roughness on surface flashover voltages under DC stress Victoria, R.; Gockenbach, L. E.; Borsi, H. 2007 Annual Report - Conference on Electrical Insulation and Dielectric Phenomena https://doi.org/10.1109/CEIDP.2007.4451562	conference	October 2007
Characteristics of electrical charging on smooth and rough surfaces of glass plates under vacuum Morita, Hiroshi; Yokosuka, Toshiyuki; Hatanaka, Ayumu IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 23, Issue 2 https://doi.org/10.1109/TDEI.2015.005265	journal	April 2016
Soft X-ray Optimization Studies on a Dense Plasma Focus Device Operated in Neon and Argon in Repetitive Mode Wong, D.; Patran, A.; Tan, T. L. IEEE Transactions on Plasma Science, Vol. 32, Issue 6 https://doi.org/10.1109/TPS.2004.838596	journal	December 2004
Enhancing Neutron Emission From a 500-J Plasma Focus by Altering the Anode Geometry and Gas Composition Bures, Brian L.; Krishnan, Mahadevan; Madden, Robert E. IEEE Transactions on Plasma Science, Vol. 38, Issue 4 https://doi.org/10.1109/TPS.2010.2042621	journal	April 2010
The Dense Plasma Focus: A Versatile Dense Pinch for Diverse Applications Krishnan, Mahadevan IEEE Transactions on Plasma Science, Vol. 40, Issue 12 https://doi.org/10.1109/TPS.2012.2222676	journal	December 2012
Production of a Highly Ionized Ion Beam by a Plasma Focus Hirano, Katsumi; Yamamoto, Toshikazu; Shimoda, Katsuji Journal of the Physical Society of Japan, Vol. 58, Issue 10 https://doi.org/10.1143/JPSJ.58.3591	journal	October 1989
Effects of Roughening Insulator Surface on Charging and Flashover Characteristics of a Long Glass Insulator in Vacuum Yamamoto, Osamu; Satoh, Takehiro; Hayashi, Hirotaka IEEJ Transactions on Fundamentals and Materials, Vol. 126, Issue 8 https://doi.org/10.1541/ieejfms.126.769	journal	January 2006
NIST Atomic Spectra Database, NIST Standard Reference Database 78 Kramida, Alexander; Ralchenko, Yuri National Institute of Standards and Technology https://doi.org/10.18434/T4W30F	dataset	January 1999

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