The application of first order many-body theory to the calculation of the differential and integral cross sections for the electron impact excitation of the 2¹S, 2¹P, 2³S, 2³P states of helium

The first order form of the many-body theory for inelastic scattering (called random phase approximation) has been applied in the 29.6 eV<or=E<or=81.63 eV energy region for the electron impact excitation of the 21S, 21P, 23S, 23P states of helium. Differential and integral cross sections are calculated and compared with recent experiments. The results for each state are discussed and compared with other calculations.