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Title: Using neutral beams as a light ion beam probe (invited)

By arranging the particle first banana orbits to pass near a distant detector, the light ion beam probe (LIBP) utilizes orbital deflection to probe internal fields and field fluctuations. The LIBP technique takes advantage of 1) the in situ, known source of fast ions created by beam-injected neutral particles that naturally ionize near the plasma edge, and 2) various commonly available diagnostics as its detector. These born trapped particles can traverse the plasma core on their inner banana leg before returning to the plasma edge. Orbital displacements (the forces on fast ions) caused by internal instabilities or edge perturbing fields appear as modulated signal at an edge detector. Adjustments in the q-profile and plasma shape that determine the first orbit, as well as the relative position of the source and detector, enable studies under a wide variety of plasma conditions. This diagnostic technique can be used to probe the impact on fast ions of various instabilities, e.g. Alfvén eigenmodes (AEs) and neoclassical tearing modes, and of externally-imposed 3D fields, e.g. magnetic perturbations. To date, displacements by AEs and by externally applied resonant magnetic perturbation fields have been measured using a fast ion loss detector. Comparisons with simulations are shown. Additionally,more » nonlinear interactions between fast ions and independent AE waves are revealed by this technique.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [3] ;  [5] ;  [3] ;  [6] ;  [4] ;  [7]
  1. Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)
  2. Univ. of California, Irvine, CA (United States)
  3. General Atomics, San Diego, CA (United States)
  4. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  5. Univ. of Texas, Austin, TX (United States)
  6. Columbia Univ., New York, NY (United States)
  7. Univ. of California, Los Angeles, CA (United States)
Publication Date:
Grant/Contract Number:
FC02-04ER54698
Type:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 85; Journal Issue: 11; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)
Research Org:
General Atomics, San Diego, CA (United States)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
OSTI Identifier:
1352930

Chen, Xi, Heidbrink, William W., Van Zeeland, Michael A., Kramer, Gerrit J., Pace, David C., Petty, Craig C., Austin, Max E., Fisher, Raymond K., Hanson, Jeremy M., Nazikian, Raffi, and Zeng, L.. Using neutral beams as a light ion beam probe (invited). United States: N. p., Web. doi:10.1063/1.4889733.
Chen, Xi, Heidbrink, William W., Van Zeeland, Michael A., Kramer, Gerrit J., Pace, David C., Petty, Craig C., Austin, Max E., Fisher, Raymond K., Hanson, Jeremy M., Nazikian, Raffi, & Zeng, L.. Using neutral beams as a light ion beam probe (invited). United States. doi:10.1063/1.4889733.
Chen, Xi, Heidbrink, William W., Van Zeeland, Michael A., Kramer, Gerrit J., Pace, David C., Petty, Craig C., Austin, Max E., Fisher, Raymond K., Hanson, Jeremy M., Nazikian, Raffi, and Zeng, L.. 2014. "Using neutral beams as a light ion beam probe (invited)". United States. doi:10.1063/1.4889733. https://www.osti.gov/servlets/purl/1352930.
@article{osti_1352930,
title = {Using neutral beams as a light ion beam probe (invited)},
author = {Chen, Xi and Heidbrink, William W. and Van Zeeland, Michael A. and Kramer, Gerrit J. and Pace, David C. and Petty, Craig C. and Austin, Max E. and Fisher, Raymond K. and Hanson, Jeremy M. and Nazikian, Raffi and Zeng, L.},
abstractNote = {By arranging the particle first banana orbits to pass near a distant detector, the light ion beam probe (LIBP) utilizes orbital deflection to probe internal fields and field fluctuations. The LIBP technique takes advantage of 1) the in situ, known source of fast ions created by beam-injected neutral particles that naturally ionize near the plasma edge, and 2) various commonly available diagnostics as its detector. These born trapped particles can traverse the plasma core on their inner banana leg before returning to the plasma edge. Orbital displacements (the forces on fast ions) caused by internal instabilities or edge perturbing fields appear as modulated signal at an edge detector. Adjustments in the q-profile and plasma shape that determine the first orbit, as well as the relative position of the source and detector, enable studies under a wide variety of plasma conditions. This diagnostic technique can be used to probe the impact on fast ions of various instabilities, e.g. Alfvén eigenmodes (AEs) and neoclassical tearing modes, and of externally-imposed 3D fields, e.g. magnetic perturbations. To date, displacements by AEs and by externally applied resonant magnetic perturbation fields have been measured using a fast ion loss detector. Comparisons with simulations are shown. Additionally, nonlinear interactions between fast ions and independent AE waves are revealed by this technique.},
doi = {10.1063/1.4889733},
journal = {Review of Scientific Instruments},
number = 11,
volume = 85,
place = {United States},
year = {2014},
month = {8}
}