Laser Thomson scattering system applicable to low-temperature plasma in the divertor simulator MAP-II

A laser Thomson scattering system was developed for the measurement of electron temperature in low-temperature recombining plasmas. The system is equipped with a double monochromator instead of an interference filter array to obtain narrow Doppler broadening. The system was applied to electron temperature measurement in the divertor simulator MAP-II. When the electron temperature is lowered to 2 eV by puffing hydrogen gas, a signature of hydrogen molecular-assisted recombination (${\mathrm{H}}_2$ -MAR) is observed.