Design of efficient soft X-ray laser using neonlike Fe driven by iodine laser

In this contribution we outline our program aimed at obtaining an efficient soft x-ray laser at the wavelength 25.5 nm, using collisional excitation in a neonlike iron plasma. The goal of the research that we are pursuing is to develop a relatively small-scale soft x-ray laser that would be accessible for a variety of applications. A driver available for us is the laser iodine photodissociation laser system PERUN, providing on the order of 40 joules in on the order of 400 ps (FWHM) pulses at the fundamental wavelength 1.315 micrometer. Theoretical analysis based on Z-scaling as well as detailed computer modeling of neonlike Fe plasmas suggest driving energies of approximately equals 15 Jcm ^-1 should be sufficient to generate high gain coefficients (up to 7 cm ^-1) on the J equals 0 minus 1 line at 25.5 nm. The modeling reveals that a 1.315 micrometer iodine driver is more efficient in producing J equals 0 minus 1 amplification in this moderate-Z system than a 1.06 micrometer Nd:glass driver. As optimizing of pumping conditions is imperative for the feasibility of the project, we have started our experimental effort by investigating plasmas analogous to those created by a small-level prepulse, i.e. by intensities ranging from approximately 5 multiplied by 10 ⁹ to approximately 1.3 multiplied by 10 ¹¹ Wcm ^-2. Preliminary results of this study are discussed elsewhere in this Proceedings.