A 64 Å Ne-like Ge X-ray laser resonantly photo-pumped by Ly-α Mg radiation

A new laboratory X-ray laser is proposed which lases between single electron holes involving several 2s→2p transitions between 64 and 89 Å in neon-like germanium and which is photo-pumped by a 2p→1s emission line in hydrogen-like magnesium. The bar over the 2s and 2p states represents a single electron hole in an otherwise closed L shell configuration. The lasing occurs with quantum efficiencies as high as 13% on these inner shell transitions. Lasing is also enhanced on several 3p→3s transitions in Ne-like Ge which would be expected to lase from collisional excitations and recombination processes, therefore it should be much easier to observe the photo-pumping process on these longer wavelength transitions as it will increase an already finite exponential gain. Calculations of the gain of these transitions in steady-state equilibrium plasmas are presented.