Drozdenko M. Electron beam formation for X-ray investigation methods

The aim of this work is to study the physical regularities of the formation of electron and X-ray beams for the problems of X-ray analysis and the creation of a laboratory installation based on a precision electron source. A beam-forming network was calculated, designed and implemented in the course of experiment on basis of a plate tungsten-rhenium indirectly heated cathode to realize X-ray fluorescence analysis and X-ray imaging. Optimal parameters of a cathode node were simulated on an electron-optical system with the finite integral technique to obtain current of a focused electron beam on a target at least 1 mA. Topology of the beam formation in an interelectrode gap, its transportation and focusing on the target to obtain a high-brightness X-ray source is shown. Basing on a calculated and simulated electron-optics network, a multipurpose laboratory facility is constructed for realization of X-ray fluorescence analysis and X-ray imaging so as to perform X-ray fluorescence analysis in atmospheric conditions and in a vacuum chamber. Viability of the chosen network based on a plate tungsten-rhenium directly heated cathode with an adjusted geometry of electrodes is theory-based and experimentally proven. A model of an X-ray spectrometer with a secondary target is suggested which differs from a classical model in polycapillary X-ray lenses available in gaps of X-rays propagations. Thus, analytical parameters of the X-ray fluorescent spectrometers are increased considerably. X-ray fluorescence spectrometers are compared with a developed technique which involves element sensitivity definition and its normalization by current of electron beam of the X-ray tube and experiment live time. The analytical properties of the developed facility was shown equally to the high-level worldwide X-ray spectrometers like MiniPal, XPRISM, Spectro2000 and Niton XL3t.