A Travelling Optical Thomson Scattering Diagnostic in Support of ARPA-E's Fusion-Energy Program

ARPA‐E supports the exploration and development of potentially transformative fusion‐energy concepts. Multi‐point, spatially and temporally resolved measurements of plasma parameters and their spatial profiles would greatly benefit these fusion experiments by establishing the level of performance that has been achieved. We have developed an optical Thomson scattering system to investigate plasma parameters including electron density, electron temperature, ion temperature, and flow velocity. Scattering of a 532nm, 1.6ns, 8 J Nd-YAG probe laser is collected from 8 points within the plasma column and delivered by a fiber bundle to 2 spectrometers with gated CMOS cameras. One spectrometer is dedicated to the electron plasma wave, while the other records the ion acoustic wave. In addition, a fraction of the laser is used to perform shadowgraphy simultaneously with the Thomson scattering measurement, providing the location probed by the laser with respect to the plasma. We will present our initial deployment on the shear flow Z-pinch machine FuZE at ZAP Energy inc. to measure the electron temperature and density along with initial data.