Setup and Calibration of a Heavy Ion Beam Probe System on MST
J. Lei, T. P. Crowley, U. Shah, K. A. Connor, P. M. Schoch, J. G. Schatz, D. R. Demers (Rensselaer Polytechnic Institute)

A heavy ion beam probe (HIBP) has been designed to measure MST plasma equilibrium and fluctuating potential, equilibrium and fluctuating magnetic field, and fluctuating electron density. Setup of this diagnostic system consists of preparing the following: 1) a 200keV accelerator which is used to launch focused potassium, lithium or sodium ions into the MST plasma; 2) primary beam line which includes a primary sweep system used to change the injection angles; 3) secondary beam line which has secondary sweep plates to direct the secondary beam into the analyzer; 4) energy analyzer which is used to detect the secondary beam current and energy; 5) other sub-systems such as vacuum system, control system and high voltage system, etc. Calibration of the system includes: 1) primary sweep calibration by a beam detector array; 2) obtaining the gain curve of the energy analyzer. After the setup and calibration, this beam probe system will be ready to diagnose the MST plasma.