Measurement of density profiles with pressure in MAP-II and DiPS linear devices

Abstract

Radial profiles of plasma density and electron temperature have been measured by a fast-scanning probe (FSP) system with various neutral pressures in the AMP-H and DiPS linear devices for the divertor simulation. The probe system is made of three probe tips, two of which is for a Mach probe consisting of two opposite-directional probes, and one is for an emissive probe installed on the pneumatically driven fast-scanning system with stroke of 30 cm. In AMP-H, density at the center has been varied from 1.5 x 10(13) cm(-3) to 0.7 x 10(13) cm(-3) with pressures of 5.5 to 112 mtorr, while that of DiPS varied from 3.5 x 10(12) cm(-3) to 9 x 10(12) cm(-3) with pressures of 0.8 to 50 mtorr. Relation of density profile with the working pressure/magnetic field is analyzed by using a simple fluid model. Electron temperature at the center is also measured by the Thomson scattering method and compared with those of FSP, which is varied from 0.6 to 65 eV.