A SIMPLE, HIGH-PERFORMANCE THOMSON-SCATTERING DIAGNOSTIC FOR HIGH-TEMPERATURE PLASMA RESEARCH

This Thomson-scattering diagnostic is used to measure the electron temperature and density of the plasma in the Madison Symmetric Torus reversed-field pinch, a magnetic confinement fusion research device. This diagnostic system is unique for its type in that it combines high performance with simple design and low-cost components. In the design of this instrument, careful attention was given to suppression of stray laser line light with simple and effective beam dumps, viewing dumps, apertures and a holographic edge filter. This allows use of a single-grating monochromator for dispersion of the Thomson scattered spectrum onto the microchannel plate detector. Alignment and calibration procedures for the laser beam delivery system, the scattered light collection system, and the spectrometer and detector are described. A sample Thomson-scattered spectrum illustrates typical data.