REINVESTIGATION OF THE DUGUAY SOFT-X-RAY LASER - A NEW PARAMETER SPACE FOR HIGH-POWER FEMTOSECOND LASER-PUMPED SYSTEMS

The innershell photoionisation soft X-ray laser proposed by Duguay and Rentzepis [Appl. Phys. Lett. 10 (1967) 350] is investigated. Based on dynamic calculations, we propose a new operating regime at high atomi c densities (similar to 10(17) cm(-3)) for this lasing system which is suitable for the recently developed short pulse (< ps) high power(> 1 0(12) W) laser systems. At high densities, a short rising edge of the soft X-ray pumping radiation is shown to be critical for high gain per formance. The calculated gain duration suggests that this laser could be operated as a sub-picosecond laser using traveling wave excitation. (C) 1997 Elsevier Science B.V.