关键词: 线圈安装误差, 误差场, 误差场概率密度分布

Abstract:

Error field caused by non-coaxiality among poloidal and toroidalfield coils on HL-2M tokamak is calculated with SURFMN and SURFMN_TFCOIL code. According to the coil installation error chosen by international tokamak and the installation experience of HL-2A tokamak, the maximum shift distance of poloidal- and toroidal-field coils on HL-2M tokamak is chosen 3~8mm, and the maximum tilt angle of that is 0.05~0.1 degree. The probability density and accumulative probability of error field are calculated with the maximum shift distance 3mm, 5mm and 8mm respectively, and the maximum tilt angle 0.05, 0.075 and 0.1 degree respectively. The results show that: (1) the probability density distribution become flat and the range of error field B_3-mode/B_T is enlarged significantly with the increase of maximum shift distance of field coils; (2) the shift of poloidal- and toroidal-field coils influences error field more heavily than tilt does; (3) when the shift of poloidal- and toroidal-field coils reaches 5mm, especially 8mm, the error field is more possibly reach 2×10^-4.

Key words: Coil installation errors, Error fields, Error field probability density distributions