Laser-induced effects on the aluminium He-β transition

Strong oscillating electric fields modify the emission spectra of ions and can result in the appearance of additional field-induced satellites, field ionisation, and alter spectral line shapes. In addition, these high fields may alter the atomic kinetics. Experiments observing these strong oscillating electric fields in highly ionised systems are limited. Here we describe experiments using a combination of long and short pulse lasers to look for field-induced satellites, and spectral line shape modification in uniform well-characterised plasmas. A hydrogen-like and helium-like aluminium plasma was preformed using a long-duration (∼1 ns), moderate intensity (∼1014 W/cm2) laser pulse. A second short-duration (10 ps), high-intensity (∼5×1016 W/cm) laser pulse was propagated transversally through this plasma to locally modify the oscillating electric field. The X-ray spectra were recorded using high-dispersion, high-luminosity spectrometers providing spatial resolution. Current analysis indicates that the predicted strong field effects have not been identified.