Differential and integrated cross sections for the electron excitation of the 4 1Po state of calcium atom

Differential cross section (DCS) data for excitation of the 4 1Po state (2.93 eV) of Ca atoms by electrons have been obtained using a crossed electron-atom beam technique. The measurements were divided into two groups. The first one consists of measurements at 10, 20, 40, 60 and 100 eV impact electron energies from 10 to 100 scattering angle interval. The second group of measurements are those at larger scattering angles (100-1500) at the same energies except 100 eV. Absolute values have been obtained by normalizing generalized oscillator strengths (GOS) to optical oscillator strength (OOS) in the minimum momentum transfer squared (K2) limit. Integral, momentum transfer and viscosity cross sections have been determined from DCSs. A comparison is made with existing relativistic distorted wave calculation