The present status of the development of a high-power KrF laser system, Ashura, is described. The main amplifier has generated 710 J (95 ns) at the pumping density of 1·lMW/cm3 with the wall plug efficiency of 2·0%. Maximum power of 9·0 GW (200 J/22 ns) per beam has been obtained from the beam lines of six-time pulse multiplexing. Power density of 1 × 1014 W/cm2 has been achieved on target with a 10−6 pre-pulse.

No abstract

No abstract

The feasibility of using high-power pulsed lasers (several tens of joules per pulse) to produce plasmas as soft X-ray sources for contact microscopy is discussed and demonstrated for a wide range of biological and other material. As in other forms of X-ray microscopy, complicated and probably artefact-inducing specimen preparation is not necessary. The short pulse lengths of the lasers mean that, for single shot exposures, images can be obtained before radiation damage has altered the structure of the specimen, and this higher resolutions are possible, in principle, than for other forms of X-ray microscopy.

No abstract

No abstract

Fundamental parameters are studied for the detailed design of a picosecond high power KrF laser system. The saturation energy density of 2.3 mJ/cm 2 and gain recovery time of 1.9 ns in an e-beam pumped KrF laser are observed. A 6 ps pulse is amplified to 1.9 J. The system at the Electrotechnical Laboratory is expected to deliver 10 ps pulses with total energy of several tens of joules in several beams.

No abstract