1s2s2p(2)3p 6L - 1s2p(3)3p 6p transitions in OIV, FV and NeVI

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 thin carbon foil target. Some observed lines are assigned to the 1s2s2p(2)3p L-6-1 s2p(3)3p P-6 electric-dipole transitions in 0 IV, F V and Ne VI, and are compared with the results of multi-configuration Hartree-Fock (with QED and higher-order corrections) and multi-configuration Dirac-Fock calculations. 31 new lines have been identified. The sextet systems of boronlike ions are possible candidates for x-ray and VUV lasers.