Bremsstrahlung isochromat from nickel: Effects of incident-electron energy and final-state symmetry

Abstract

We report the bremsstrahlung isochromat at a quantum energy of 5414 eV from clean nickel surfaces prepared in an ultrahigh-vacuum environment. This spectrum does not merely reflect the density of vacant states in nickel, nor is it the same as spectra recorded at 530 and 1214 eV, respectively, by other workers: the assumption of symmetry independence of the transition probability for bremsstrahlung isochromats from solids is not justified. The bremsstrahlung isochromats from nickel, at three different quantum energies, are well approximated by spectra synthesized by adding partial densities of states, calculated by Szmulowicz, weighted by an appropriate symmetry-dependent radiative electron-capture cross section, calculated after Hahn and Rule.