ELECTRON-IMPACT EXCITATION OF BERYLLIUM

Results from an R-matrix with pseudo-states (RMPS) calculation are pre sented for electron impact excitation of the (2s(2))S-1 --> (2s2p)P-1, 3(o) transitions in beryllium for incident energies from threshold up to 5 Ryd. At energies above the ionization threshold (0.685 Ryd), the representation of target continuum states is found to be crucial for a ccurate results to be obtained. A significant reduction, of up to a fa ctor of two compared to the results of Fon et al, is found for the cro ss sections in this energy range. This result has important implicatio ns regarding the use of currently available e-Be cross section data fo r plasma diagnostics.