Observation of the toroidal rotation in a new designed compact torus system for EAST

TL;DR

This paper reports the observation of plasma rotation and preliminary results from a new compact torus injection system designed for the EAST tokamak, demonstrating promising parameters for future tokamak fueling.

Contribution

It introduces a new compact torus injection system for EAST and provides initial experimental observations of plasma rotation and density evolution.

Findings

Plasma velocity reached 56 km/s

Electron density achieved 8.73×10^20 m^(-3)

Significant plasma rotation observed during formation

Abstract

Compact torus injection is considered as a high promising approach to realize central fueling in the future tokamak device. Recently, a compact torus injection system has been developed for the Experimental Advanced Superconducting Tokamak, and the preliminary results have been carried out. In the typical discharges of the early stage, the velocity, electron density and particles number of the CT can reach 56.0 km/s, 8.73*10^20 m^(-3) and 2.4*10^18 (for helium), respectively. A continuous increase in CT density during acceleration was observed in the experiment, which may be due to the plasma ionized in the formation region may carry part of the neutral gas into the acceleration region, and these neutral gases will be ionized again. In addition, a significant plasma rotation is observed during the formation process which is introduced by the E*B drift. In this paper, we present the detailed system setup and the preliminary platform test results, hoping to provide some basis for the exploration of the CT technique medium-sized superconducting tokamak device in the future