ANGULAR-DISTRIBUTION OF CASCADE X-RAYS FOLLOWING RADIATIVE RECOMBINATION FROM A BEAM

Calculations are carried out for the cross section for x-ray emission by n = 2 and 3 states resulting from the radiative recombination onto bare and hydrogenlike ions of titanium and iron from a beam of electrons with energies of several kilo electron volts. The calculation includes the contribution coming from direct recombination and cascades from higher-energy states. The density matrix of the magnetic sublevels is included in the calculation and results are given for the emission at 90-degrees to the direction of the incoming electron beam and its degree of linear polarization. The calculation is carried out relativistically assuming the incoming electrons move in a central potential. The bound states of the heliumlike ions are treated using a configuration-interaction code using basis states derived from a relativistic average-configuration Hartree-Fock code for the calculation of both the radiative-recombination and bound-state transition-matrix elements.