Two Pulse and Multiple Position Thomson Scattering System

Abstract
A Thomson scattering system for simultaneous measurements of the electron temperature and density at ten different positions at two times during a single plasma shot has been developed for Heliotron E. The apparatus consists of two ruby lasers, each delivering two pulses whose temporal separation is typically 100 ms; light collection optics including automatic positioning mechanisms; 80 detectors; and a data processing system. We have obtained spatial profiles of T e (0.05–1.3 keV) and n e (0.2-9.0×1019 m-3) in Heliotron E for each plasma shot.