First observation of lasing at 231 Å in neon-like nickel using the prepulse technique

We report lasing for the first time in nickel on the neon-like J=0→1, 3p→3s transition at 231 Å as well as several weaker transitions including the J=2»1 lines at 298 Å and 304 Å. Amplification is seen only when the prepulse technique of using a low intensity prepulse before the main optical drive pulse is used to illuminate the nickel target. The prepulse technique is also shown to produce lasing in copper and dramatically improve the output of the germanium laser.