Absolute K-shell ionization cross sections and L alpha and L beta(1) x-ray production cross sections of Ga and As by 1.5-39-keV electrons

摘要

Absolute K-shell ionization and L alpha and L beta(1) x-ray production cross sections for Ga and As have been measured for incident electrons in the energy range from 1.5 to 39 keV. The cross sections were deduced from K alpha, L alpha, and L beta(1) x-ray intensities emitted from ultrathin GaAs samples deposited onto self-supporting carbon films. The x-ray intensities were measured on an electron microprobe equipped with several wavelength-dispersive spectrometers and were converted into absolute cross sections by using estimated values of the target thickness, spectrometer efficiency, and number of incident electrons. Experimental results are compared with cross sections calculated from the plane-wave and distorted-wave Born approximations, the relativistic binary-encounter-Bethe model, the results of two widely used simple analytical formulas, and, whenever possible, experimental data from the literature.