Short pulse x-ray laser 32.6 nm based on transient gain in Ne-like titanium

A novel two-step excitation scheme for an efficient table-top x-ray laser has been realized for the first time. A nanosecond pulse creates a plasma of neonlike ions of titanium, followed by a subpicosecond pulse which excites a nonstationary population inversion. With only a few joules of pump energy, a compact x-ray laser at 32.6 nm with a very high gain coefficient of g = 19 cm(-1) and a gain-length product of gL = 9.5 was achieved.