In:
Nuclear Fusion, IOP Publishing, Vol. 51, No. 10 ( 2011-10-01), p. 103034-
Abstract:
A source describing the injection of fast ions due to the ionization of high-energy neutral beams has been added to the surface-averaged quasilinear Fokker–Planck code SSFPQL (Brambilla 1994 Nucl. Fusion 34 1121 ). For this purpose, the multiple-beam NBI code SINBAD (Feng et al 1995 Comput. Phys. Commun. 88 161) has been included as a module in SSFPQL, with the modifications required to handle arbitrary axisymmetric equilibria. Alternatively, the neutral beam injection (NBI) source can be built using the output of a Monte Carlo NBI code. We have also added a term describing losses of fast ions during thermalization, and a subroutine evaluating the neutron production rate by nuclear reactions. With these extensions, iterations between SSFPQL and the full-wave solver TORIC (Brambilla 1999 Plasma Phys. Control. Fusion 41 1 ) can now be used to investigate the strong interplay between NBI and ion cyclotron (IC) heating. By comparing the predicted and measured neutron production rates from D–D reactions in a discharge with combined NBI and IC heating in ASDEX Upgrade we obtain a plausible estimate of the importance of fast-ion losses (FILs), even if their cause cannot be identified. We find, however, that the plasma composition, in particular the presence of low Z impurities, plays a more critical role than FILs in limiting the efficiency of this heating scheme.
Type of Medium:
Online Resource
ISSN:
0029-5515
,
1741-4326
DOI:
10.1088/0029-5515/51/10/103034
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2011
detail.hit.zdb_id:
2037980-8
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