NE-LIKE ION LASERS IN THE EXTREME-ULTRAVIOLET REGION

We report strong J=0-1, 3p-3s lasing in Ne-like scandium, calcium, pot assium, and chlorine at wavelengths ranging from 35.3 nm in scandium t o 52.9 nm in chlorine. The experiments were carried out with the ASTER IX IV iodine laser using a 15% prepulse 5.2 ns before the main pulse. These results extend the range of laser plasma x-ray lasers into the e xtreme ultraviolet region. Gain lengths between 7 and 11 were measured for the different lines. The 38.3-nm laser in calcium lased at an int ensity as low as 5x10(12) W/cm(-2).