Prague Asterix Laser System (PALS): results and upgrades

The PALS multi-user laser facility has been offering the beam time to the groups of both domestic and foreign rsearchers since September 2000. During the past two years of operation of its terawatt iodine laser system, a number of technical innovations and new diagnostic options were implemented, the most important of which are described in the paper. A brief survey of the current PALS research program is also given. Laser plasma sources of x-radiation and of highly stripped ions represent the two main lines followed. Recent highlights include the development and application of a highly coherent double-pass XUV laser based on Ne-like zinc. The reported studies of material response to the XUV pulses are mainly motivated by a potential use of the observed ablation phenomena e.g. in nanotechnology, while the x-ray contact microscopy permitted to image living biological objects with a resolution comparable to that of the electron microscopy. The PALS laser system is now in a routine operation, which opens the way to its new upgrades. The progress reached with the key ones -- application of elements of adaptive optics, replacement the original iodine oscillator by a solid-state based one, and, most important, implementation of the optical parametric chirped pulse amplification (OPCPA) technique -- is also reported.