Anomalous satellite-line intensities from a TRIDENT laser-produced plasma

An unusual enhancement of two normally-weak and density-stable satellite sp ectral lines resulting from 2s(2)-1s2p and 1s2s(2)-1s(2)2p transitions in H e- and Li-like ions of silicon has been observed in laser-produced plasma e xperiments at the TRIDENT facility. Space-resolved intensities compared to other more-intense satellites formed by dielectronic recombination are incr eased by a factor as high as 8 over code predictions at low density (corona l limit). The data were obtained using temporally- and spatially resolved X -ray spectroscopic measurements, supported by Thomson scattering diagnostic s. One explanation considered is that the more-intense satellite lines are opacity limited. This suggests a method of determining radiative transfer o n the more intense lines, by comparison measurements. Also coincident with these two enhanced features is a K-alpha blend from low stages of ionizatio n, which suggests some alternate interpretation, A complete understanding o f the observed anomalies awaits further experimentation. (C) 2000 Elsevier Science Ltd. All rights reserved.