Installation of an advanced heavy ion beam diagnostic on the TJ-II stellarator

Abstract

An advanced 200 keV heavy ion beam diagnostic has been developed for the TJ-II stellarator based on the simultaneous utilization of a 30° Proca-Green electrostatic energy analyzer and a multiple cell array detector. This innovative design allows instantaneous measurements of plasma potential and electron density profiles together with their respective fluctuations. In this article we present a description of the main parts of a heavy ion beam diagnostic (injection system, detectors, and control and data acquisition system) and the results obtained during the first operation on TJ-II. The problems of plasma loading of the detectors and hard x-ray generation associated with the probing beam are reported. © 2001 American Institute of Physics.