An Ion Beam Pumped X-Ray Laser - A Progress Report

This work reports progress toward an ion-atom collision-pumped, traveling wave x-ray laser. The prototype system now under construction seeks to stimulate the emission of photons from L vacancies induced in intense 50 keV Al+ beams during their passage through thin aluminum films. An analytical study of the conditions required of the medium and the ion sources needed to produce it indicates that carefully focused and bunched ion pulses from an electrohydrodynamic (EHD) source may be pumped to inversion, provided their overall space charge is neutralized by electron pick-up. During recently completed testing of a developmental At EHD source unfocused, unbunched fluxes of about 25% of the desired ion current level were produced. An improved EHD source is now being built and will soon be used in a study of the soft x-ray outputs from foil excited dense ion beams under non-inverted and later, perhaps, inverted conditions.