Delta f Monte Carlo Calculation Of Neoclassical Transport In Perturbed Tokamaks

Kim, Kimin ; Park, Jong-Kyu ; Kramer, Gerrit ; Boozer, Allen H.

关键词: Computer Simulation;    Transport Theory;   

DOI  :  10.2172/1063119
RP-ID  :  PPPL-4752
PID  :  OSTI ID: 1063119

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

Non-axisymmetric magnetic perturbations can fundamentally change neoclassical transport in tokamaks by distorting particle orbits on deformed or broken flux surfaces. This so-called non-ambipolar transport is highly complex, and eventually a numerical simulation is required to achieve its precise description and understanding. A new delta f particle code (POCA) has been developed for this purpose using a modi ed pitch angle collision operator preserving momentum conservation. POCA was successfully benchmarked for neoclassical transport and momentum conservation in axisymmetric con guration. Non-ambipolar particle flux is calculated in the non-axisymmetric case, and results show a clear resonant nature of non-ambipolar transport and magnetic braking. Neoclassical toroidal viscosity (NTV) torque is calculated using anisotropic pressures and magnetic fi eld spectrum, and compared with the generalized NTV theory. Calculations indicate a clear B2 dependence of NTV, and good agreements with theory on NTV torque pro les and amplitudes depending on collisionality.