skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Study of the time-resolved, 3-dimensional current density distribution in solid metallic liners at 1 MA

Abstract

We present a study of the time varying current density distribution in solid metallic liner experiments at the 1MA level. Measurements are taken using an array of magnetic field probes which provide 2D triangulation of the average centroid of the drive current in the load at 3 discrete axial positions. These data are correlated with gated optical self-emission imaging which directly images the breakdown and plasma formation region. Results show that the current density is azimuthally non-uniform, and changes significantly throughout the 100ns experimental timescale. Magnetic field probes show clearly motion of the current density around the liner azimuth over 10ns timescales. If breakdown is initiated at one azimuthal location, the current density remains non-uniform even over large spatial extents throughout the current drive. The evolution timescales are suggestive of a resistive diffusion process or uneven current distributions among simultaneously formed but discrete plasma conduction paths.

Authors:
 [1];  [1];  [1]; ORCiD logo [2]; ORCiD logo [2];  [2];  [2];  [2]; ORCiD logo [2]
  1. Univ. of California, San Diego, CA (United States)
  2. Cornell Univ., Ithaca, NY (United States). Lab. for Plasma Studies
Publication Date:
Research Org.:
DOE
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1417971
Grant/Contract Number:
NA0001836
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 23; Journal Issue: 9; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Bott-Suzuki, S. C., Cordaro, S. W., Caballero Bendixsen, L. S., Atoyan, L., Byvank, T., Potter, W., Kusse, B. R., Greenly, J. B., and Hammer, D. A. Study of the time-resolved, 3-dimensional current density distribution in solid metallic liners at 1 MA. United States: N. p., 2016. Web. doi:10.1063/1.4963249.
Bott-Suzuki, S. C., Cordaro, S. W., Caballero Bendixsen, L. S., Atoyan, L., Byvank, T., Potter, W., Kusse, B. R., Greenly, J. B., & Hammer, D. A. Study of the time-resolved, 3-dimensional current density distribution in solid metallic liners at 1 MA. United States. doi:10.1063/1.4963249.
Bott-Suzuki, S. C., Cordaro, S. W., Caballero Bendixsen, L. S., Atoyan, L., Byvank, T., Potter, W., Kusse, B. R., Greenly, J. B., and Hammer, D. A. 2016. "Study of the time-resolved, 3-dimensional current density distribution in solid metallic liners at 1 MA". United States. doi:10.1063/1.4963249. https://www.osti.gov/servlets/purl/1417971.
@article{osti_1417971,
title = {Study of the time-resolved, 3-dimensional current density distribution in solid metallic liners at 1 MA},
author = {Bott-Suzuki, S. C. and Cordaro, S. W. and Caballero Bendixsen, L. S. and Atoyan, L. and Byvank, T. and Potter, W. and Kusse, B. R. and Greenly, J. B. and Hammer, D. A.},
abstractNote = {We present a study of the time varying current density distribution in solid metallic liner experiments at the 1MA level. Measurements are taken using an array of magnetic field probes which provide 2D triangulation of the average centroid of the drive current in the load at 3 discrete axial positions. These data are correlated with gated optical self-emission imaging which directly images the breakdown and plasma formation region. Results show that the current density is azimuthally non-uniform, and changes significantly throughout the 100ns experimental timescale. Magnetic field probes show clearly motion of the current density around the liner azimuth over 10ns timescales. If breakdown is initiated at one azimuthal location, the current density remains non-uniform even over large spatial extents throughout the current drive. The evolution timescales are suggestive of a resistive diffusion process or uneven current distributions among simultaneously formed but discrete plasma conduction paths.},
doi = {10.1063/1.4963249},
journal = {Physics of Plasmas},
number = 9,
volume = 23,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share:
  • In the context of low temperature plasma research, we propose a wall current probe to determine the local charged particle fluxes flowing to the chamber walls. This non-intrusive planar probe consists of an array of electrode elements which can be individually biased and for which the current can be measured separately. We detail the probe properties and present the ability of the diagnostic to be used as a space and time resolved measurement of the ion and electron current density at the chamber walls. This diagnostic will be relevant to study the electron transport in magnetized low-pressure plasmas.
  • An experimental investigation of the laser produced plasma induced shock wave in the presence of confining walls placed along the axial as well as the lateral direction has been performed. A time resolved Mach Zehnder interferometer is set up to track the primary as well as the reflected shock waves and its effect on the evolving plasma plume has been studied. An attempt has been made to discriminate the electronic and medium density contributions towards the changes in the refractive index of the medium. Two dimensional spatial distributions for both ambient medium density and plasma density (electron density) have beenmore » obtained by employing customised inversion technique and algorithm on the recorded interferograms. The observed density pattern of the surrounding medium in the presence of confining walls is correlated with the reflected shock wave propagation in the medium. Further, the shock wave plasma interaction and the subsequent changes in the shape and density of the plasma plume in confined geometry are briefly described.« less
  • The temporal characteristics of the Xe{sup +} ion axial velocity distribution function (VDF) were recorded in the course of low-frequency discharge current oscillations ({approx}14 kHz) of the 5 kW class PPS X000 Hall thruster. The evolution in time of the ion axial velocity component is monitored by means of a laser induced fluorescence diagnostic tool with a time resolution of 100 ns. As the number of fluorescence photons is very low during such a short time period, a homemade pulse-counting lock-in system was used to perform real-time discrimination between background photons and fluorescence photons. The evolution in time of themore » ion VDF was observed at three locations along the thruster channel axis after a fast shutdown of the thruster power. The anode discharge current is switched off at 2 kHz during 5 {mu}s without any synchronization with the current oscillation cycle. This approach allows to examine the temporal behavior of the ion VDF during decay and ignition of the discharge as well as during forced and natural plasma oscillations. Measurements show that the distribution function of the axial component of the Xe{sup +} ion does change periodically in time with a frequency close to the current oscillation frequency in both forced and natural cases. The ion density and the mean velocity are found to oscillate, whereas the velocity dispersion stays constant, which indicates that ionization and acceleration layers have identical dynamics. Finally, variations over time in the electric field are for the first time experimentally evidenced in a crossed-field discharge.« less
  • 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.