SOLPS analysis of neutral baffling for the design of a new diverter in DIII-D

摘要

Using the SOLPS5.0 code, an assessment has been undertaken of the relative importance of two key aspects of divertor baffle geometry: (i) divertor closure, and (ii) field-target angle. The figures of merit (FOMs) have been taken to be achieving specified (low) values of electron temperature at the target, T_(et), and parallel power flux density at the target, q║_t, at the lowest possible 'upstream' density, n_(e,sep,OMP), for a given power input. As expected, it was found that increased closure for both orthogonal targets and small glancing-angle targets make for a better divertor, based on these FOMs. It was also found that the combination of these aspects is significantly more effective than either aspect separately. The latter appears to be related to a strong correlation between T_(et) and deuterium gas density at the target, which is the subject of a companion paper (Stangeby P.C. and Sang C.F. 2017 Nucl. Fusion 57 056007).