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

Title: Interpretation of runaway electron synchrotron and bremsstrahlung images

Abstract

The crescent spot shape observed in DIII-D runaway electron synchrotron radiation images is shown to result from the high degree of anisotropy in the emitted radiation, the finite spectral range of the camera and the distribution of runaways. The finite spectral camera range is found to be particularly important, as the radiation from the high-field side can be stronger by a factor 106 than the radiation from the low-field side in DIII-D. By combining a kinetic model of the runaway dynamics with a synthetic synchrotron diagnostic we see that physical processes not described by the kinetic model (such as radial transport) are likely to be limiting the energy of the runaways. We show that a population of runaways with lower dominant energies and larger pitch-angles than those predicted by the kinetic model provide a better match to the synchrotron measurements. Using a new synthetic bremsstrahlung diagnostic we also simulate the view of the gamma ray imager diagnostic used at DIII-D to resolve the spatial distribution of runaway-generated bremsstrahlung.

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [1]
  1. Chalmers Univ. of Technology (Sweden)
  2. General Atomics, San Diego, CA (United States)
  3. Univ. of California, San Diego, CA (United States)
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States); Univ. of California, San Diego, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1456291
Alternate Identifier(s):
OSTI ID: 1500217
Grant/Contract Number:  
FC02-04ER54698
Resource Type:
Journal Article: Published Article
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 8; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Hoppe, M., Embréus, O., Paz-Soldan, C., Moyer, R. A., and Fülöp, T. Interpretation of runaway electron synchrotron and bremsstrahlung images. United States: N. p., 2018. Web. doi:10.1088/1741-4326/aaae15.
Hoppe, M., Embréus, O., Paz-Soldan, C., Moyer, R. A., & Fülöp, T. Interpretation of runaway electron synchrotron and bremsstrahlung images. United States. doi:10.1088/1741-4326/aaae15.
Hoppe, M., Embréus, O., Paz-Soldan, C., Moyer, R. A., and Fülöp, T. Fri . "Interpretation of runaway electron synchrotron and bremsstrahlung images". United States. doi:10.1088/1741-4326/aaae15.
@article{osti_1456291,
title = {Interpretation of runaway electron synchrotron and bremsstrahlung images},
author = {Hoppe, M. and Embréus, O. and Paz-Soldan, C. and Moyer, R. A. and Fülöp, T.},
abstractNote = {The crescent spot shape observed in DIII-D runaway electron synchrotron radiation images is shown to result from the high degree of anisotropy in the emitted radiation, the finite spectral range of the camera and the distribution of runaways. The finite spectral camera range is found to be particularly important, as the radiation from the high-field side can be stronger by a factor 106 than the radiation from the low-field side in DIII-D. By combining a kinetic model of the runaway dynamics with a synthetic synchrotron diagnostic we see that physical processes not described by the kinetic model (such as radial transport) are likely to be limiting the energy of the runaways. We show that a population of runaways with lower dominant energies and larger pitch-angles than those predicted by the kinetic model provide a better match to the synchrotron measurements. Using a new synthetic bremsstrahlung diagnostic we also simulate the view of the gamma ray imager diagnostic used at DIII-D to resolve the spatial distribution of runaway-generated bremsstrahlung.},
doi = {10.1088/1741-4326/aaae15},
journal = {Nuclear Fusion},
issn = {0029-5515},
number = 8,
volume = 58,
place = {United States},
year = {2018},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1088/1741-4326/aaae15

Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

Save / Share: