2019年6月29日 五室第110期研讨会

2019629 五室第110期研讨会

题  目:A relativistic model of electron cyclotron current drive efficiency in tokamak plasmas

报告人胡业民

时  间:2019年6月29日(星期六)  9:00—9:50

摘  要:

Electron cyclotron current drive (ECCD) has been considered an im-portant tool for current profile control to achieve high performance in ITER operation owing to its ability to drive local current on- and off-axis. An accurate and computationally efficient model of ECCD efficiency is highly desirable for the purpose of performing scenario modeling and in-between shots data analysis for EC experiments on ITER. From theoret-ical studies in the past, it is clear that both momentum-conserving and relativistic characteristics are needed in the electron-electron collision op-erator to appropriately describe the collisional relaxation [1, 2, 3]]processes in the high temperature plasmas. In this work, numerical calculations of the current drive efficiency in a tokamak by using the variational approach are performed. A fully relativistic extension of the variational principle with the modified test function for the Spitzer function with momen-tum conservation in the electron-electron collision is described in general tokamak geometry [4, 5, 6]]. The model developed has generalized that of Marushchenko’s[2], which is extended for arbitrary temperatures and covers exactly the asymptotic for u  1 when Zeff  1, and suited to ray-tracing calculations. Also the wave-particle interaction is modeled by the relativistic generalization of the local Kennel-Engelman wave-induced dif-fusion operator in velocity space [7]. The theoretical results obtained here have been used to upgrade the current drive package in the ray-gracing code TORAY-GA, the benchmark has been made and the calculated re-sults were in good agreement with that using CQL3D. The upgraded code can also be used in other EC ray-tracing codes.

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