skip to main content


Title: Validating predictive models for fast ion profile relaxation in burning plasmas

The redistribution and potential loss of energetic particles due to MHD modes can limit the performance of fusion plasmas by reducing the plasma heating rate. In this work, we present validation studies of the 1.5D critical gradient model (CGM) for Alfvén eigenmode (AE) induced EP transport in NSTX and DIII-D neutral beam heated plasmas. In previous comparisons with a single DIII-D L-mode case, the CGM model was found to be responsible for 75% of measured AE induced neutron deficit [1]. A fully kinetic HINST is used to compute mode stability for the non-perturbative version of CGM (or nCGM). We have found that AEs show strong local instability drive up to $$\gamma /\omega \sim 20\%$$ violating assumptions of perturbative approaches used in NOVA-K code. Lastly, we demonstrate that both models agree with each other and both underestimate the neutron deficit measured in DIII-D shot by approximately a factor of 2.
 [1] ;  [2] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1] ;  [3] ; ORCiD logo [1]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Univ. of California, Irvine, CA (United States)
  3. General Atomics, San Diego, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-09CH11466; AC03-99ER54463; FC02-04ER54698; SC-G903402
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 56; Journal Issue: 11; Conference: 14. IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems, Vienna (Austria), 1-4 Sep 2015; Journal ID: ISSN 0029-5515
IOP Science
Research Org:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; alpha particles; Alfvénic modes; magnetic fusion; reduced quasi-linear model
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1267533; OSTI ID: 1347154