Theory Verification and Numerical Bnchmarking on Neoclassical Toroidal Viscosity Torque
Authors: Z. Wang, et. al.
Abstract:
Systematic veri cation and numerical benchmarking have been success-
fully carried out among three di erent approaches of neoclassical toroidal
viscosity (NTV) theory and the corresponding codes: IPEC-PENT is devel-
oped based on the combined NTV theory but without geometric simpli -
cations [1]; MARS-Q includes smoothly connected NTV formula [2] based
on Shaing's analytic formulation in various collisionality regimes; MARS-
K, originally computing the drift kinetic energy, is upgraded to compute
the NTV torque based on the equivalence between drift kinetic energy and
NTV torque [3]. The derivation and numerical results both indicate that the
imaginary part of drift kinetic energy computed by MARS-K is equivalent to
the NTV torque in IPEC-PENT. In the benchmark of precession resonance
between MARS-Q and MARS-K/IPEC-PENT, the agreement and correla-
tion between the connected NTV formula and the combined NTV theory
in di erent collisionality regimes is shown for the rst time. Additionally,
both IPEC-PENT and MARS-K indicate the importance of the bounce har
monic resonance which can greatly enhance the NTV torque when E X B
drift frequency reaches the bounce resonance condition.
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Submitted to: Physics of Plasmas (October 2013)
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Download PPPL-4960 (pdf 2.49 MB 24 pp)
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