Investigations of low 𝑞𝑎 discharges in the SINP tokamak

Pramana

S Lahiri1¹  A N S Iyengar¹  R Pal¹  S Kukhopadhyay¹ 

[1] Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064, India$$

关键词: Safety factor;    tokamak;    current density;    MHD;    stability.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Low edge safety factor discharges including very low 𝑞𝑎 (1 < 𝑞𝑎 < 2) and ultra low 𝑞𝑎 (0 < 𝑞𝑎 < 1) have been obtained in the SINP tokamak. It has been observed that accessibility of these discharges depends crucially on the fast rate of plasma current rise. Several interesting results in terms of different time scales like 𝑇𝑞𝑎, 𝜏𝑅 etc have been obtained using a set of softwares developed at SINP. From fluctuation analysis of the external magnetic probe data it has been found that MHD instabilities 𝑚 = 1, 𝑛 = 1 and 𝑚 = 2, 𝑛 = 1 etc. play major role in the evolution of these discharges. To investigate the internal details of these discharges, an internal magnetic probe system has been developed using which current density 𝑗𝜙 and other related parameters have been estimated. By carrying out a resistive stability analysis, evidence of the above-mentioned MHD instabilities have again been found. The physical processes lying behind the accessibility and evolution of the low 𝑞𝑎 discharges have been thoroughly investigated.

【 授权许可】

Unknown