ELECTRON-SCATTERING FROM HELIUM-ATOMS - PHASE-SHIFTS, RESONANCE PARAMETERS AND TOTAL CROSS-SECTIONS

The 'R-matrix with pseudostates' (RMPS) method has been used to calcul ate low-energy phase shifts, positions and widths of resonances near t he n = 2 thresholds, integrated cross sections for all transitions bet ween the 1(1)S, 2(3)S, 2(1)S, 2(3)P(0) and 2(1)P(0) states of helium, and ionization cross sections at total collision energies up to 80 eV. The use of sophisticated target states has enabled accurate results t o be obtained at low energies; and good agreement with results from th e 'convergent close-coupling' (CCC) method and the available experimen tal data to be obtained at intermediate energies.