A new x-ray laser scheme is proposed that lases on Balmer (beta) transitions from 2.87 nm to 5.99 nm in H-like ions and is resonantly photopumped by Ly (gamma) radiation from the same kind of H-like ions. Optimization designing for targets and driving laser conditions is carried out using simulation codes. A recombining plasma produced from a slab target irradiated by a 50 ps drive pulse is found to be the ideal pump plasma to provide maximum Ly (gamma) line radiation. Numerical calculations predict that the high gain coefficients on Balmer (beta) transitions of H-like ions with atomic number Z equals 9 to 13 can potentially be achieved with this scheme.
Michael H. Key,
"Photopumped Balmer β X-ray lasers", Proc. SPIE 1928, International Symposium on Laser-Plasma Interactions, (10 September 1993); doi: 10.1117/12.155765; https://doi.org/10.1117/12.155765