EVALUATION OF RADIAL PARTICLE-FLUX PROFILE BASED ON A ATOMIC-HYDROGENDENSITY-MEASUREMENTS USING LASER-INDUCED FLUORESCENCE AND EMISSION ATH-ALPHA

Local atomic hydrogen densities inside plasmas of the Compact Helical System (CHS) were measured using laser induced fluorescence tuned to H -alpha, and the results were compared with those calculated using a ne utral particle simulation code, in order to determine the penetration energy of hydrogen atoms from the chamber wall into the plasma. The re sults of these and supplementary measurements of H-alpha emission inte nsities using CCD cameras and photomultipliers at various toroidal pos itions yielded local atomic hydrogen density distributions throughout the whole plasma. The distribution of the particle source rate was eva luated from the atomic hydrogen distribution, and then the radial part icle flux profile was obtained from a particle continuity equation. Es timated errors for the latter were +/- 30% at an absolute level and se veral per cent in the profile shape. The radial particle flux thus obt ained is valuable for evaluations of particle diffusion coefficient an d convection velocity.