The 4p-4dTransitions of Y VI, VII, VIII, Zr VII, VIII, IX, Nb VIII, IX, X and Mo IX, X, XI

On recordings made in the Physics Department of Lund University, we have identified 64, 65, 63 and 71 4 p -4 d transitions in Y VI, Zr VII, Nb VIII and Mo IX, respectively, establishing 23 levels of 4 p 3 4 d in each case. In Y VII, Zr VIII, Nb IX and Mo X we have identified 54, 53, 48 and 57 4 p -4 d transitions, establishing 19 levels of 4 p 2 4 d in each spectrum. The number of 4 p -4 d transitions identified in Y VIII, Zr IX, Nb X and Mo XI is 28, 27, 27 and 31; they establish all the 11 4 p 4 d levels that can combine with the ground levels. In addition, two levels of 4 s 4 p 3 could be found from 4 s -4 p transitions.