Measurements of Stark-broadened Balmerαandγlines of He ii in dense plasmas

Abstract

We have measured profiles of optically thin Balmer α and γ lines of He i i at 164 and 108.5 nm in a homogeneous hydrogen plasma using a microchannel-plate detector. The electron density of the plasma is between 5×${10}^{23}$ and 8×${10}^{23}$ ${\mathrm{m}}^{\mathrm{-}3}$ at temperatures of about 10 eV. The measured line profiles and full widths at half maximum are compared with various calculations and measurements. We find agreement for the Balmer α line within the experimental errors of approximately 25%. The Balmer γ line is less broadened than expected from the calculation of Kepple, as found in two earlier experiments.