Electron Temperature and Density Distributions in a Divertor Simulation Experimental Module with Gas Injection in GAMMA 10/PDX

In tandem mirror GAMMA 10/PDX, H₂ gas has been injected to a divertor simulation experimental module (D-module) for radiation cooling and detachment study. Electron temperature (T_e) and density (n_e) distributions have been measured by Langmuir probes in the D-module. With increase of H₂ gas amount, T_e has decreased especially at the V-shaped target plate from 30-40 eV to 3-5 eV. Moreover, n_e and ion saturation current I_is have increased at the inlet but decreased at the target and had a steeper distribution toward the corner. These results suggest detachment. The movement of the ionization front to the upstream side with increase of the gas is suggested from the change in the plasma parameters profiles along the magnetic field line.