Helium spectral lineshapes in a dense, cool, z-pinch plasma

Abstract
Measurements of the He I 587.6 nm (23P-33D) line-shift-to-width ratio in a dense (1.3-3.5*1024 m-3), cool 2.5-4.0*104 K z-pinch plasma are reported. Despite difficulties imposed by the radial gradients present in this plasma, a change in the sign of the lineshift and asymmetry dependent on the density and temperature conditions was unambiguously observed. This is in qualitative agreement with recent calculations.