Cross sections of the 3p-1 diagram and satellite Auger states in atomic calcium for electron impact

The Ca 3p ionization cross sections of the diagram Anger states 3p(5)4s(2) P-2(3/2), P-2(1/2) and of specific satellite Auger states were measured for electron impact from threshold up to 1.5 keV incident energy. Energies, multi-configuration compositions and relative high-energy cross sections of the Auger states were obtained theoretically by using the multi-configuration Hartree Fock method including relaxation of outer electrons in the sudden approximation. For the cross section ratios of satellite Auger states relative to the diagram state 3p54s2 2P1/2 We found a strong energy dependence caused by the dynamics of shakeup transitions at low impact energies and, in addition, by strong admixtures of quarter state components. The experimental satellite-to-diagram cross section ratios at high impact energies agree well with the present calculation and with values obtained from photoionization data if the difference in the dynamics between photoionization and electron impact ionization is taken into account.