THE NEON-LIKE YTTRIUM COLLISIONAL LASER

We have investigated the Ne-like yttrium collisionally pumped laser us ing a detailed time dependent collisional radiative model within a flu id code (EHYBRID), and post-processors to investigate the effects of r efraction and saturation. We conclude that, in addition to that on the two J = 2 --> 1 lines, gain is generated on the J = 0 --> 1 transitio n and that this line very closely overlaps the J = 2 --> 1 transition at 155 angstrom. A 50% reduction in the calculated monopole excitation rate which pumps the J = 0 --> 1 line (a notoriously uncertain quanti ty) is required to obtain satisfactory agreement with experiment - the same modification as was required for the germanium laser.