We present a general expression for the maximum ion energy observed in experiments with thin foils irradiated by high-intensity laser pulses. The analytical model is based on a radially confined surface charge set up by laser accelerated electrons on the target rear side. The only input parameters are the properties of the laser pulse and the target thickness. The predicted maximum ion energy and the optimal laser pulse duration are supported by dedicated experiments for a broad range of different ions.

We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. We investigate the stability and decomposition of alloys containing 1 alkali metal atom, Li, Na, or K ͑M 1 ͒; and 1 alkali, alkaline earth or 3d / 4d transition metal atom ͑M 2 ͒ plus two to five ͑BH 4 ͒ − groups, i.e., M 1 M 2 ͑BH 4 ͒ 2-5 , using a number of model structures with trigonal, tetrahedral, octahedral, and free coordination of the metal borohydride complexes. Of the over 700 investigated structures, about 20 were predicted to form potentially stable alloys with promising decomposition energies. The M 1 ͑Al/ Mn/ Fe͒͑BH 4 ͒ 4 , ͑Li/ Na͒Zn͑BH 4 ͒ 3 , and ͑Na/ K͒͑Ni/ Co͒͑BH 4 ͒ 3 alloys are found to be the most promising, followed by selected M 1 ͑Nb/ Rh͒͑BH 4 ͒ 4 alloys.

Expressions for the double and triple differential cross sections for K-shell ionisation by relativistic electrons are derived with the plane wave impulse approximation (PWIA). Assuming the bound atomic electrons to be on-shell, the double differential cross section factorises in essence into the Moller cross section and the Compton profile. The triple differential off-shell cross section is given for Moller and Bhabba scattering. The results are compared with experimental data.

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Transitions from the 21P1 - and 23P1 -state to the ground state 11S0 in helium-like sulphur ions have been measured with an accuracy of 4 × 10-5. Energy calibration is described in detail and two reference wavelengths have been reevaluated. Substantial line-blending was observed, due to long-lived spectator electrons. The two transition energies were corrected for Doppler shift and compared with most refined theoretical calculations, including terms of order α4Z6 in the Breit operator and terms of order α5Z6 in the quantum-electrodynamical corrections. The experimental contributions to the ground-state QED shifts agree within its error (∼ 15%) with the theoretical values.