skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on April 14, 2017

Title: Phase space effects on fast ion distribution function modeling in tokamaks

Here, integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities,ad-hocmodels can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions. The kick model implemented in the tokamaktransport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability throughmore » the analysis of the power exchanged between energetic particles and the instabilities.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Publication Date:
OSTI Identifier:
1254686
Report Number(s):
PPPL--5218
Journal ID: ISSN 1070-664X; PHPAEN
Grant/Contract Number:
AC02-09CH11466
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 23; Journal Issue: 5; Related Information: The digital data for this paper can be found in http://arks.princeton.edu.ezproxy.princeton.edu/ark:/88435/dsp018p58pg29; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY magnetohydrodynamics; tokamaks, NSTX; transport phenomena; wave interaction; particles; phase space methods; particle distribution functions; neutrons; instability analysis; plasma transport properties