New method of error elimination in potential profile measurement of tokamak plasmas by high voltage heavy ion beam probes

摘要

The measurement of a potential profile in tokamak plasmas by heavy ion beam probe (HIBP) in a single shot is usually difficult, because as primary beam is swept through plasma cross-section, the secondary beam hits the input slit of an energy analyzer with a large variation in entrance angles (in-plane and out-plane). In this paper, a new method (the application of fast toroidal sweeps of the primary or the secondary beam at the analyzer or at an entrance to an tokamak) is proposed to eliminate the error due to the change in the entrance angle. In addition, results of a new calibration method of HIBP in tokamak (electron stripping by neutral gas) are presented. (author). (ERA citation 18:007227)