Measurements of x ray production cross sections by electron impact

Abstract

Electron impact ionization data are of great importance in many applications associated with the characterization of materials, in addition to be fundamental in understanding of the electron-atom collision processes. Cross section measurements are still known with little precision, around 10-20%, depending on the analyzed shell/subshell and the atomic number, mostly for K shell, and for a limited number of elements and energies. In this project we propose to obtain cross section measurements of K and L x-ray production of elements of intermediate atomic number (5M ~ 3050) by electron impact of 10 keV, or from the element's K ionization threshold, up to 100 keV. This research will be carried out in collaboration with the Instituto de Física da Universidade de São Paulo, where the experiments were carried out at Microtron of São Paulo. Currently, it supplies electrons with energy between 10 and 100 keV and direct current, in the interval of 1 nA to 10 ¼A. The results will be compared with those found in the literature, and with the theoretical calculations that are accepted today as the state of the art on the subject.