Open AccessNeutral Particle Analyzer Vertically Scanning Measurements of MHD-induced Energetic Ion Redistribution or Loss in the National Spherical Torus Experiment
Author(s) -
S. S. Medley,
R. André,
R. E. Bell,
D.S. Darrow,
C.W. Domier,
E. D. Fredrickson,
N.N. Gorelenkov,
S. M. Kaye,
B. LeBlanc,
K.C. Lee,
F.M. Levinton,
D. Liu,
Neville C. Luhmann,
J.E. Menard,
H. Park,
D. Stutman,
A. L. Roquemore,
K. Tritz,
H. Yuh
Publication year - 2007
Language(s) - English
Resource type - Reports
DOI - 10.2172/961736
Subject(s) - atomic physics , magnetohydrodynamics , ion , neutral beam injection , neutral particle , physics , plasma , tokamak , nuclear physics , quantum mechanics
Observations of magneto-hydro-dynamic (MHD) induced redistribution or loss of energetic ions measured using the vertically scanning capability of the Neutral Particle Analyzer diagnostic on the National Spherical Torus Experiment (NSTX) are presented along with TRANSP and ORBIT code analysis of the results. Although redistribution or loss of energetic ions due to bursting fishbone-like and low-frequency (f ~ 10 kHz) kinktype MHD activity has been reported previously, the primary goal of this work is to study redistribution or loss due to continuous Alfvénic (f ~ 20 – 150 kHz) modes, a topic that heretofore has not been investigated in detail for NSTX plasmas. Initial indications are that the former drive energetic ion loss whereas the continuous Alfvénic modes only cause redistribution and the energetic ions remain confined