Gaussian Models for the Energy Distribution of Excitation in Solids: Applications to X-Ray Microanalysis and Solid State Electronics

Gaussian models for the depth distribution of excitation in a solid bombarded by an electron beam have been successfully applied to the interpretation of data obtained in electron probe x-ray microanalysis (spatial resolution and absorption effects) and to the study of voltage dependence of cathodoluminescence and the voltage dependence of electron beam induced currents at Schottky barriers. In these applications, it was assumed that the distribution of excitation with depth can be scaled in depth according to the range-energy equation: R = CEno. The physical basis for this range-energy equation is the Bethe equation for electron energy loss, which yields the Bethe range when integrated over the electron\u27s path in the target. The Bethe range was previously shown by Hoff and Everhart to be of the form R = CEno over the range of energies useful in most experiments with electron beam excitation

Dual cathode system for electron beam instruments

An electron beam source having a single electron optical axis is provided with two coplanar cathodes equally spaced on opposite sides from the electron optical axis. A switch permits selecting either cathode, and a deflection system comprised of electromagnets, each with separate pole pieces equally spaced from the plane of the cathodes and electron optical axis, first deflects the electron beam from a selected cathode toward the electron optical axis, and then in an opposite direction into convergence with the electron optical axis. The result is that the electron beam from one selected cathode undergoes a sigmoid deflection in two opposite directions, like the letter S, with the sigmoid deflection of each being a mirror image of the other

Design and Development of an Electronic X-Ray Probe for the Study of Alloys and of the Structure of Metals

Progress on the design and development of an electronic x-ray microprobe for quantitative and qualitative composition measurements of about 1 cubic micron of the surface of metals and alloys is described in this report. The principle is that first used by Castaing, in which the metal is subjected to bombardment by a finely focused probe of electrons and the elements present and their proportions are determined by an analysis of the frequency and intensity of the characteristic x-rays emitted. With the first model of the instrument, it will be possible to study the elements in the ranges of atomic numbers 19 through 34 and 50 through 84. This report omits any theoretical treatment of the effects of heat generated in the sample, fluorescence radiation, or a detailed discussion of the corrections that must be made. These matters will be considered in a later report