ELECTRON-IMPACT EXCITATION OF BORON

Results from an R-matrix with pseudo-states (RMPS) calculation are pre sented for electron-impact excitation of the (2s(2)2p)P-2(o) --> (2s2p (2))P-4, (2s(2)2p)P-2(o) --> (2s(2)3s)S-2 and (2s(2)2p)P-2(o) --> (2s2 p(2))D-2 transitions in neutral boron for incident energies from thres hold up to 3 Ryd. At energies above the ionization threshold (0.61 Ryd ), the inclusion of target continuum states in the close-coupling expa nsion is found to be crucial for accurate results to be obtained. Comp ared to previous first-order distorted-wave and R-matrix calculations with only discrete states, the present work represents a significant i mprovement in the prediction of the total excitation cross sections in the above energy range.