Beam-foil Spectroscopy of the 1s2s2p23p 6L-1s2p33p 6P Transitions in O IV, F V and Ne VI

We present observations of VUV transitions between doubly excited sextet states in O IV, F V and Ne VI. Spectra were produced by collisions of an O+, (FH)+ and Ne+ beam with a solid carbon target. Some observed lines are assigned to the 1s2s2p23p 6L-1s2p33p 6P electric-dipole transitions in O IV, F V and Ne VI, and are compared with results of MCHF (with QED and higher-order corrections) and MCDF calculations. 31 new lines have been identified. The sextet systems of boronlike ions are possible candidates for x-ray and VUV lasers.