Radial Compression to Transiently Achieve Higher Beta Poloidal in a Tokamak

Abstract

An increase in the magnetic strength of the vertical field will, in general, compress and heat plasmas, which thus allows high temperature, high density, and high beta to be reached. In this paper, according to the scaling laws for the magnetic compression, the scaling range of both the major-radius compression and the minor-radius compression is figured out. Then, the comparison between the major-radius compression and the minor-radius compression is carried out. It demonstrates that the minor-radius compression can obtain higher ${\beta }_{p}$ of plasma. Consequently, we try to significantly enhance discharge parameters by the minor-radius compression by inserting the sets of the vertical-field coils in the experimental advanced superconducting tokamak (EAST) vacuum chamber. Afterward, the minor-radius compression based on EAST shot #34128 is deduced with ${C}_{a}=1.5$ and ${C}_{R}=0.925$ , which increases ${\beta }_{p}$ by 76.19%. It notes that the minor-radius compression is a promising way to effectively improve ${\beta }_{p}$ in a tokamak. Finally, the preliminary design of the minor-radius compression, which includes the control system, the in-vessel vertical-field coils, and its fast-control power supply, is described.