First Order Finite-Orbit-Width Corrections. in CQL3D Ion Fokker-Planck Modeling of the NSTX HHFW Experiment

摘要

Experiments that combine high harmonic fast wave ion cyclotron range of frequency(ICRF) heating and neutral beam injection (NBI) on the National Spherical Tokamak Experiment exhibit significant radio-frequency acceleration of NBI-generated fast ions with energies up to 90 keV. At such high energies, the finite orbit width (FOW) of the fast ions has been found important for accurately modeling diagnostics[1,2,3] such as the FIDA (fast ion D-Alpha) diagnostic[4]. A synthetic diagnostic based on the zero-orbit-width (ZOW) CQL3D Fokker-Planck (FP) code[5] has calculated a FIDA signature of fast ions that is shifted inwards with respect to observations[1,2]. The work reported here discusses application of a first order FOW correction to GQL3D and to the FIDA synthetic diagnostic. A