Intensity distribution of the focal lines of the prepulse and mainpulse atthe solid target surface

At the Prague Asterix Laser System (PALS) the former Asterix iodine laser o f the Max-Planck-Institut fur Quantenoptik is currently re-installed. For t he x-ray laser experiments that will be performed in the near future a well defined focal line at the position of the target surface is crucial. Apply ing the prepulse technique there are two possibilities, either the main bea m and the prepulse beam are focused by the same focusing optics or the two different beams are focused by two optical systems separately. It is import ant to characterise the intensity distribution of the both line foci in two dimensions (along and across the focal line), since their energy ratio is giving only a mean value and not the actually existing non-uniformity's alo ng or across the focal line. By using two different focusing optics it is p ossible that the two line foci do not have exactly the same width. In order to realise a well defined prepulse line focus it is necessary to measure t he intensity distribution in two dimensions. We concept a method to obtain quantified two-dimensional focal images and we present preliminary experime ntal results using a cylindrical lens array as well as using only a single cylindrical lens in combination with a spherical focusing lens.