High-gain x-ray lasing at 111 nm in sodiumlike copper driven by a 20-J, 2-ps Nd:glass laser

Abstract
Evidence of high gain pumped by recombination has been observed in the 5g−4f transition at 11.1 nm in sodiumlike copper ions with use of a 20-J 2-ps Nd:glass laser system. The time- and space-integrated gain coefficient was 8.8 ± 1.4 cm−1, indicating a single-transit amplification of ∼60 times. This experiment has shown that 2 ps is the optimum pulse duration to drive the sodiumlike copper recombination x-ray lasing at 11.1 nm.