Progress in the Development of a Compact Capillary Discharge Soft X-Ray Laser

We have proposed compact and efficient soft X-Ray recombination lasers could be demonstrated by direct discharge excitation of a capillary plasma [1,2]. In this laser scheme a dense and nearly totally ionized plasma core with a large length-to-diameter ratio (L/d = 10-100) is created from a fast discharge by ionizing material from the capillary walls. Subsequent rapid plasma cooling by heat conduction to the capillary walls and radiation results in recombination of highly ionized species into ions of lower charge, creating population inversions and amplification of soft X-Ray radiation.