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Title: Generation and suppression of runaway electrons in MST tokamak plasmas

Abstract

This paper discusses the behavior of runaway electrons in tokamak plasmas at low electron density, plasma current, and magnetic field using experimental data from the Madison Symmetric Torus and computational data from the NIMROD nonlinear resistive 3D MHD code. Density thresholds for the onset and suppression of runaway electrons are determined experimentally in steady tokamak plasmas, and in plasmas with a population of runaway electrons, resonant magnetic perturbations with different poloidal mode numbers are applied. Poloidal mode number m = 3 perturbations suppress the runaway electrons, while perturbations with m = 1 have little effect. This difference is consistent with the difference in computed magnetic topologies. The m = 1 RMP has minimal effect on the topology, while the m = 3 RMP produces a broad region of stochasticity, which can allow for rapid loss of the runaway electrons.

Authors:
ORCiD logo [1];  [2];  [2];  [3];  [2];  [2];  [2];  [2]
  1. Univ. of Wisconsin, Madison, WI (United States); General Atomics, San Diego, CA (United States)
  2. Univ. of Wisconsin, Madison, WI (United States)
  3. Univ. of Wisconsin, Madison, WI (United States); Naval Research Lab. (NRL), Washington, DC (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1602423
Grant/Contract Number:  
FC02-05ER54814; FC02-08ER54975; SC0018001; SC0020245
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 60; Journal Issue: 4; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; runaway electrons; resonant magnetic perturbations; tokamak; MHD

Citation Formats

Munaretto, Stefano, Chapman, B. E., Cornille, B. S., DuBois, A. M., McCollam, K. J., Sovinec, C. R., Almagri, A. F., and Goetz, J. A. Generation and suppression of runaway electrons in MST tokamak plasmas. United States: N. p., 2020. Web. doi:10.1088/1741-4326/ab73c0.
Munaretto, Stefano, Chapman, B. E., Cornille, B. S., DuBois, A. M., McCollam, K. J., Sovinec, C. R., Almagri, A. F., & Goetz, J. A. Generation and suppression of runaway electrons in MST tokamak plasmas. United States. https://doi.org/10.1088/1741-4326/ab73c0
Munaretto, Stefano, Chapman, B. E., Cornille, B. S., DuBois, A. M., McCollam, K. J., Sovinec, C. R., Almagri, A. F., and Goetz, J. A. 2020. "Generation and suppression of runaway electrons in MST tokamak plasmas". United States. https://doi.org/10.1088/1741-4326/ab73c0. https://www.osti.gov/servlets/purl/1602423.
@article{osti_1602423,
title = {Generation and suppression of runaway electrons in MST tokamak plasmas},
author = {Munaretto, Stefano and Chapman, B. E. and Cornille, B. S. and DuBois, A. M. and McCollam, K. J. and Sovinec, C. R. and Almagri, A. F. and Goetz, J. A.},
abstractNote = {This paper discusses the behavior of runaway electrons in tokamak plasmas at low electron density, plasma current, and magnetic field using experimental data from the Madison Symmetric Torus and computational data from the NIMROD nonlinear resistive 3D MHD code. Density thresholds for the onset and suppression of runaway electrons are determined experimentally in steady tokamak plasmas, and in plasmas with a population of runaway electrons, resonant magnetic perturbations with different poloidal mode numbers are applied. Poloidal mode number m = 3 perturbations suppress the runaway electrons, while perturbations with m = 1 have little effect. This difference is consistent with the difference in computed magnetic topologies. The m = 1 RMP has minimal effect on the topology, while the m = 3 RMP produces a broad region of stochasticity, which can allow for rapid loss of the runaway electrons.},
doi = {10.1088/1741-4326/ab73c0},
url = {https://www.osti.gov/biblio/1602423}, journal = {Nuclear Fusion},
issn = {0029-5515},
number = 4,
volume = 60,
place = {United States},
year = {2020},
month = {3}
}

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