PROFILES OF THE HE-I 2(3)P-3(3)D LINE AT HIGH-DENSITIES

We report on measurements of Stark profiles of the He I 2(3)P-3(3)D tr ansition at lambda = 587.6 nm performed in a plasma of the gas-liner p inch discharge. The line shape and peak shift have been measured at de nsities in the range of n(e) = 0.5-2.5 x 10(18) cm(-3) and temperature s of k(B) T = 4-5.5 eV and compared with theoretical calculations usin g several approximations. The plasma parameters were determined indepe ndently by Thomson scattering. For higher densities the width of the H e I 2(3)P-3(3)D transition grows nonlinearly with increasing density, and the shift of the line center shows a change of the sign from a blu e to a red shift. For lower densities the Stark width and shift are ex cellently predicted by the calculations, but, as expected, for higher densities the agreement becomes worse, especially for the shift, when the validity range of the approximations is exceeded.