Method for remote control of radiation parameters of spacecraft based on X-ray fluorescence analysis

Existing international legal acts, instruments and procedures do not guarantee equal conditions for the exploration and use of outer space. There is a need for means of objective control of spacecraft carrying products with fissile materials. Inspection of such objects can be carried out by X-ray fluorescence methods. However, in the subject area under consideration, the use of such methods has been little studied. In this paper, a method is proposed for obtaining the spectra of X-ray fluorescence radiation of materials, the object under study based on the calculation of the spatial and energy characteristics of X-ray radiation. The X-ray fluorescence spectra of objects are obtained on the basis of the calculation of the spatial and energy characteristics of X-ray radiation according to the original geometric (mathematical) and simulation models developed by the authors. The calculations take into account the complex layered system of the object, taking into account the proportions of high-energy fluorescent radiation of the overlying layers. An original numerical experiment is proposed using a program that allows one to choose the projections of an object subjected to X-ray irradiation, the wavelength and intensity of the emitter parameters. Using the obtained spatial-energy distribution of radiation quanta and the physical properties of the radiation transmission medium, the problem of finding the coordinates and angles of intersection of tracks of quanta beams in each area of the object is solved. The result of software processing is displayed as the resulting spectrum. The obtained spectrum makes it possible to draw a conclusion about the chemical composition of the materials of the inspected object. The X-ray beam reaching the object is modeled as a spot with an area commensurate with the cross section of the device in the form of a selected geometric primitive — a square. The spot area of the incident photons is calculated from a predetermined divergence angle. On the basis of open literary sources, a physical model of an object with nuclear fissile materials W88 (USA) was chosen. The following characteristics of X-ray beams (subbeams) are accepted: a coherent beam of photons with a wavelength of 0.005 nm; beam scattering angle of 1 degree; emitter detector area of 4 m2. The resulting X-ray fluorescence spectrum was obtained which gives an idea of the chemical composition of the units and blocks of the apparatus and the object inside. The presence of specific products on the object board is confirmed by characteristic lines with normalized wavelengths indicating the presence of chemical elements belonging to the radioactive series. The results obtained can be used in the development of hardware and software for spacecraft devices that monitor the presence of fissile materials on board of the inspected vehicle.