MEASUREMENT OF MOTIONAL STARK SPECTRUM OF A NEUTRAL BEAM EMISSION IN JIPP T-IIU PLASMA

Polarization measurements of the Balmer alpha line of a beam emission are performed using a newly developed four-polarizer optical system on the JIPP T-IIU tokamak. Poloidal magnetic held profile in a plasma is obtained successfully in current ramp-up experiments. Electron densit y dependence of the relative emissivity of sigma and pi components in the motional Stark spectra is also investigated experimentally. The re sults suggest that the relative emissivity is independent of the elect ron density in the range of 2 x 10(19)-9 x 10(19) m(-3). (C) 1997 Else vier Science B.V.