Line Opacity in X-pinch Plasmas

Self-absorption features have been observed during the compression phase of hybrid X-pinch (HXP) plasmas¹. Previous spectroscopic studies of X-pinches have estimated line opacity from time‑integrated strong/weak line ratios² . Current studies are exploring line opacity during the compression phase through time resolved strong and weak line ratios. The time- resolved ratios are used to track opacity throughout compression, inverting them with an escape factor model to yield a column density history Ner(t) and the corresponding monochromatic opacity kappa_lambda(t) of the hotspot. These experiments are performed on the XP pulsed power generator with the 450-kA peak current and a rise time of 60 ns (10 to 90%).