Soft X-ray recombination lasing by Li-like TiXX ion

Li-like ion scheme of recombination pumping mechanism is one of the most promisingapproaches to compact and efficiently saturated amplifier in the "Water Window" spectral re-gion. Recently, numerous important investigations have been made in a number of famouslaboratories worldwide and considerable progresses have been made. However, someissues on the lasing mechanism have not been quite understood yet. Especially When one at-