Speaker
Jiaxian Li
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1037.pdf
Preliminary analysis of breakdown and startup conditions for the first
plasma of HL-2M
J.X.Li, J.H.Zhang, X.M.Song, G.Y.Zheng, R.Ma, Y.D.Pan
Southwestern Institute of Physics, Chengdu, China
HL-2M is a new tokamak under construction in SWIP. In order to achieve the first plasma
on HL-2M successfully, the initial discharge breakdown and start-up conditions are analyzed
according to the engineering and physical goals of HL-2M, and the self-consistent initial
discharge parameters are designed. In this paper, we will introduce the design of the equilibrium
configuration, the compensation of the magnetic field generated by the eddy currents in the
vacuum vessel and the plasma breakdown conditions for the discharge in detail. Finally, a self-
consistent initial plasma discharge parameters are designed.
In this paper, the limiter equilibrium configuration for the initial discharge of HL-2M is
designed by EFIT. And then the divertor configurations with a low elongation are explored to
further optimize the plasma discharge control technology on HL-2M.
Since the vacuum vessel of HL-2M is designed to be conductive in the toroidal direction,
the eddy current induced in vacuum vessel before and after the breakdown of the plasma will
produces a strong vertical magnetic field in the plasma region. The vertical field destroy the
pure (regardless of eddy current effects) null magnetic field configuration, which is too bad to
the plasma breakdown and plasma current ramp-up. Therefore, this paper will explore the
compensation of the magnetic field generated by the eddy current, and then design a self-
consistent null-field configuration and give the initial plasma discharge parameters.
A preliminary estimation of the volt-second consumption in the plasma discharge process
is made based on the Ejima's coefficient and Spitzer's resistance method. Refer to the plasma
startup design on EAST and KSTAR by J.A. Leuer, the self-consistent initial plasma discharge
waveform among the plasma current, the PF coil current and the CS coil current are designed.
At the same time, the additional currents that compensate for the magnetic field generated by
the eddy currents are considered in the evolution of these waveforms.
This work was supported by National Nature Science Foundation (Grant Nos. 11505050,
11575056, 11775071) and Chinese ITER Plan Project Foundation (Grant Nos.
2015GB105001, 2015GB105004)
