ABSTRACT
When a short pulse (270 fs), short wavelength laser (248 nm) with an energy of 250 mJ is focused into a high density (1 Atm) Xe gas target composed of small atomic clusters, a region of collapsed focal propagation is produced via the physical process of relativistic and charge-displacement self-focusing. This self-focused region of highly concentrated energy, which can be maintained for many (~ 100) Rayleigh lengths, presents formidable diagnostic problems to detect and measure keV amplification from the bright X-ray source produced. The techniques presently utilized to establish amplification in the extreme vacuum ultraviolet region may not be readily applicable to the X-ray region at quantum energies exceeding about 500 eV. A new protocol for the measurement of amplification in self-focused channels is proposed.
