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Title: Measurement of runaway electron energy distribution function during high-Z gas injection into runaway electron plateaus in DIII-D

Abstract

The evolution of the runaway electron (RE) energy distribution function f{sub ε} during massive gas injection into centered post-disruption runaway electron plateaus has been reconstructed. Overall, f{sub ε} is found to be much more skewed toward low energy than predicted by avalanche theory. The reconstructions also indicate that the RE pitch angle θ is not uniform, but tends to be large at low energies and small θ ∼ 0.1–0.2 at high energies. Overall power loss from the RE plateau appears to be dominated by collisions with background free and bound electrons, leading to line radiation. However, the drag on the plasma current appears to be dominated by collisions with impurity ions in most cases. Synchrotron emission appears not to be significant for overall RE energy dissipation but may be important for limiting the peak RE energy.

Authors:
; ;  [1]; ; ;  [2]; ;  [3];  [4];  [5]
  1. University of California—San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States)
  2. General Atomics, PO Box 85608, San Diego, California 92186 (United States)
  3. Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, Tennessee 37831 (United States)
  4. Institute for Fusion Studies, University of Texas—Austin, 2100 San Jacinto Blvd, Austin, Texas 78712 (United States)
  5. Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, California 94550 (United States)
Publication Date:
OSTI Identifier:
22410388
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 22; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COLLISIONS; DOUBLET-3 DEVICE; DRAG; ELECTRIC CURRENTS; ENERGY SPECTRA; FUNCTIONS; GAS INJECTION; INCLINATION; IONS; PLASMA IMPURITIES; POWER LOSSES; RUNAWAY ELECTRONS; SYNCHROTRONS

Citation Formats

Hollmann, E. M., Moyer, R. A., Rudakov, D. L., Parks, P. B., Eidietis, N. W., Paz-Soldan, C., Commaux, N., Shiraki, D., Austin, M. E., and Lasnier, C. J. Measurement of runaway electron energy distribution function during high-Z gas injection into runaway electron plateaus in DIII-D. United States: N. p., 2015. Web. doi:10.1063/1.4921149.
Hollmann, E. M., Moyer, R. A., Rudakov, D. L., Parks, P. B., Eidietis, N. W., Paz-Soldan, C., Commaux, N., Shiraki, D., Austin, M. E., & Lasnier, C. J. Measurement of runaway electron energy distribution function during high-Z gas injection into runaway electron plateaus in DIII-D. United States. https://doi.org/10.1063/1.4921149
Hollmann, E. M., Moyer, R. A., Rudakov, D. L., Parks, P. B., Eidietis, N. W., Paz-Soldan, C., Commaux, N., Shiraki, D., Austin, M. E., and Lasnier, C. J. 2015. "Measurement of runaway electron energy distribution function during high-Z gas injection into runaway electron plateaus in DIII-D". United States. https://doi.org/10.1063/1.4921149.
@article{osti_22410388,
title = {Measurement of runaway electron energy distribution function during high-Z gas injection into runaway electron plateaus in DIII-D},
author = {Hollmann, E. M. and Moyer, R. A. and Rudakov, D. L. and Parks, P. B. and Eidietis, N. W. and Paz-Soldan, C. and Commaux, N. and Shiraki, D. and Austin, M. E. and Lasnier, C. J.},
abstractNote = {The evolution of the runaway electron (RE) energy distribution function f{sub ε} during massive gas injection into centered post-disruption runaway electron plateaus has been reconstructed. Overall, f{sub ε} is found to be much more skewed toward low energy than predicted by avalanche theory. The reconstructions also indicate that the RE pitch angle θ is not uniform, but tends to be large at low energies and small θ ∼ 0.1–0.2 at high energies. Overall power loss from the RE plateau appears to be dominated by collisions with background free and bound electrons, leading to line radiation. However, the drag on the plasma current appears to be dominated by collisions with impurity ions in most cases. Synchrotron emission appears not to be significant for overall RE energy dissipation but may be important for limiting the peak RE energy.},
doi = {10.1063/1.4921149},
url = {https://www.osti.gov/biblio/22410388}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 5,
volume = 22,
place = {United States},
year = {Fri May 15 00:00:00 EDT 2015},
month = {Fri May 15 00:00:00 EDT 2015}
}

Works referencing / citing this record:

Dynamics of positrons during relativistic electron runaway
journal, October 2018


Resolving runaway electron distributions in space, time, and energy
journal, May 2018


On the synchrotron emission in kinetic simulations of runaway electrons in magnetic confinement fusion plasmas
journal, October 2017


Spatiotemporal evolution of runaway electrons from synchrotron images in Alcator C-Mod
journal, October 2018


Kink instabilities of the post-disruption runaway electron beam at low safety factor
journal, March 2019


The effect of resonant magnetic perturbation on the electron density threshold of runaway electron generation during disruptions on J-TEXT
journal, December 2019


Dissipation of post-disruption runaway electron plateaus by shattered pellet injection in DIII-D
journal, March 2018


Physics of runaway electrons in tokamaks
journal, June 2019


MARS-F modeling of post-disruption runaway beam loss by magnetohydrodynamic instabilities in DIII-D
journal, October 2019


Effect of Partially Screened Nuclei on Fast-Electron Dynamics
journal, June 2017


Effect of partially-screened nuclei on fast-electron dynamics
text, January 2017