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This paper reports on recent results of a series of experiments on laser-generated ion beams. The experiments were done at the 30 TW ‘Trident’ laser system at the Los Alamos National Laboratories in New Mexico, USA, and we demonstrated the first accelerated ions at the 10 TW beamline of the PHELIX laser system at Gesellschaft fur Schwerionenforschung, Darmstadt, Germany. The experiments show the dependence of the Target Normal Sheath Acceleration Process (TNSA) on laser imprint and target parameters. The results are compared to a simple model for the ion propagation. It shows that TNSA-driven protons form an ion beam with superior beam quality, following the versatile spatial beam-shaping approaches.

An unusual enhancement of two normally-weak and density-stable satellite spectral lines resulting from 2s 2 –1s2p and 1s2s 2 –1s 2 2p transitions in He- and Li-like ions of silicon has been observed in laser-produced plasma experiments at the TRIDENT facility. Space-resolved intensities compared to other more-intense satellites formed by dielectronic recombination are increased by a factor as high as 8 over code predictions at low density (coronal limit). The data were obtained using temporally- and spatially resolved X-ray spectroscopic measurements, supported by Thomson scattering diagnostics. One explanation considered is that the more-intense satellite lines are opacity limited. This suggests a method of determining radiative transfer on the more intense lines, by comparison measurements. Also coincident with these two enhanced features is a K α blend from low stages of ionization, which suggests some alternate interpretation. A complete understanding of the observed anomalies awaits further experimentation.

Two types of satellite lines are studied in laser-produced plasmas as potential diagnostic tools. One consists of a pair of lines straddling the wavelength of a dipole-forbidden line and displaced from it by the laser frequency. The relative intensities are a measure of the local laser electric field in the plasma. Possible satellites of this sort associated with He-like and Li-like magnesium n = 2 to n = 3 transitions are indicated in the data. The second type of satellite arises from an innershell transition in Li-like aluminum (and magnesium) and the lines occur adjacent to the He-like ls2 1S-ls3p 1P x-ray resonance line. The upper level configuration for one satellite does not readily autoionize, and hence is populated mainly by electron collisions in a high density plasma. It is an electron density indicator, and in the present case the relative intensity is consistent with electron densities ~ 1020 cm−3, according to atomic physics modeling. The wavelengths of these Li-like innershell satellites appear to be shifted shorter by ~ 13 mA when compared to those of nearby He-like resonance lines. The sequence of such ionic x-ray lines from streak data are in agreement with a numerical code.