Crystal spectroscopy for Kα X-rays from silicon bombarded with protons and alpha particles

In this paper, an automatic Bragg spectrometer having an organic and vacuum X-ray detector is described, and the K- alpha X-ray spectra for silicon bombarded with hydrogen and helium ions are reported. Hydrogen or helium ion beam extracted from a 4 MV Van de Graaff accelerator hits a thick silicon target in a target chamber. The beam energies were between 1.0 and 2.5 MeV for hydrogen ions, and 1.5 and 2.5 MeV for helium ions. The crystal spectrometer was set in the target chamber. The X-ray emitted from the silicon target passed through a Soller slit, and hit an EDDT crystal mounted on a rotating table. The automatic display of the X-ray spectra was considered. The yield profiles of diagram and satellite X-rays emitted from silicon were obtained. The relative values of X-ray production cross-section, the atomic fluorescence yield for multi-ionized silicon, and the ionization cross-section were derived. The procedures to convert the observed yield of satellite X-ray to the multiple ionization cross-section are described. The correction for the detector sensitivity and the calculation of the atomic fluorescence yield for multi-ionized atoms are important. The mechanism of multiple ionization is discussed. (Kato, T.)