Observation of high gain in Ne-like Ag lasers

We report the observation of high-gain lasing in laser-heated exploding-foil Ag targets at pump irradiances {≥}6×{}10¹⁴ W/cm². The measured gain coefficients on the dominant Ne-like J=2{→}1 transitions are determined to be 9.4±{}1.5 cm^-1 for (2p3/2)3p3/2{→}(2p3/2)3s at 9.9365 nm and 6.4_-1.5+2.0 cm^-1 for (2p1/2)3p3/2{→}(2p1/2)3s at 10.0377 nm. These are the highest gain coefficients yet observed to our knowledge for any short-wavelength laser. Gain is observed on three other Ne-like lines including a J=0{→}1 transition at 8.1563 nm, the shortest wavelength yet observed to our knowledge for a Ne-like x-ray laser.