Ion sensitive probe measurement of divertor simulation plasma in GAMMA 10/PDX

An ion sensitive probe (ISP) has been installed in the divertor simulation module of the largest tandem mirror plasma device GAMMA 10/PDX in order to evaluate the property of the high temperature end loss plasmas. The ISP has the capability to evaluate ion temperature (Ti), electron temperature (Te), electron density and plasma space potential, simultaneously. We have tested the ISP measurement for several discharge and neutral gas pressure conditions. Tievaluated by using an ion collector of the ISP shows ∼6 eV which corresponds to the perpendicular component of Ti in principle. Te evaluated by the current-voltage characteristics of an electron guard electrode of the ISP shows ∼4 eV which is lower than Te obtained by Langmuir probes upstream and downstream of the ISP. These results indicate the existence of anisotropic ion and electron temperatures in the D-module.