Математика, 2005, ¹2 X-RAY SOURCE BASED ON THE PARAMETRIC X-RAYS MECHANISM A. Lobko, O. Lugovskaya Institute for Nuclear Problems, Belarus State University Prospects of parametric x-rays (PXR) application for the development of a tuneable quasi-monochromatic x-ray source for medical imaging are discussed. <...> Analysis of basic requirements for electron accelerator shows that it must be relatively low-energy and high-current linac. <...> In comparison with known ultra-relativistic cases, at low energies PXR properties will be modified to a great extent by multiple scattering of electrons. <...> PXR intensity dependences on target thickness and beam energy are calculated taking multiple scattering into account. <...> It is concluded that PXR source based on real medical accelerators is feasible and can provide x-ray flux needful for obtaining high quality medical images. 1. <...> INTRODUCTION Parametric x-rays (PXR) produced by a relativistic charged particle uniformly moving through a single crystal were claimed as a very attractive radiation mechanism for x-ray source since its theoretical prediction in 1972 [13] and first experimental observation in 1985 [4]. <...> Actually, it has a number of indisputable features, namely, high monochromaticity, energy tuneability, polarization, directivity, and possibility to be emitted to large angles relative to beam direction, i.e. provide monochromatic x-rays virtually free of background. <...> PXR properties were studied at a number of accelerator facilities worldwide but a PXR-based x-ray source is still not developed. <...> So, we should recognize how to design a PXR-based source that will meet the consumers requirements for its use in industry and medicine. <...> Industry and science, as consumers, essentially yield to medicine, which represents the huge market for devices and methods for x-ray diagnostics. <...> Despite the development of alternative diagnostics methods, e.g. ultrasound and magnetic resonance imaging, the number of © Lobko A., Lugovskaya O., 2005. studies in the field of x-ray diagnostics remains high. <...> These requirements can be met if the customer will be offered a monochromatic tuneable source, providing xradiation with exactly the energy required for examination of a specific organ. <...> Precise selection of monochromatic radiation energy will allow <...>