Compact and intense parametric x-ray radiation source based on a linear accelerator with cryogenic accelerating and decelerating copper structures

Abstract

This paper describes a proposal for a compact x-ray source based on parametric x-ray radiation (PXR). The PXR, which is produced when a single crystal is bombarded with relativistic electrons, has good monochromaticity and spatial coherence, and is expected to be well suited for imaging of low-Z materials and medical application. The proposed system employs a pair of copper accelerating structures which are operated at a cryogenic temperature of 20 K and arranged to form a resonant ring configuration. The electron beam is once accelerated up to 75 MeV in one of the structures, being decelerated down to lower than 7 MeV in the other structure after generating PXR at a single crystal, and then dumped. The expected x-ray yield is 10 9 photons=s at a center energy of 15 keV or higher.

Performance of K -edge subtraction tomography as an application of parametric x-ray radiation

“…When PXR sources based on new accelerators are developed that can provide substantially more photon flux than the present LEBRA-PXR source, it is expected that the dynamic range of element detection will be expanded to become a practical analytic tool [31].…”

PARAMETRIC X-ray RADIATION IN POLYCRYSTALS

“…For example, it was proposed [25] that polycrystals can be used instead of crys-tals to generate quasimonochromatic X-ray beams because of a higher resistance to mechanical damage produced by the charged particle beam. However, it was shown that the destruction of Si crystals is related to the heating during one micropulse, if the micro pulse duration is smaller than 5 μs, currents of 300 mA can be achieved [28]. Similarly, it was shown that the rocking curves obtained by PXR are wider than those obtained by commonly used diffraction methods because of the influence of the initial angular divergence of the charged particle Coulomb field [17].…”

Superradiant parametric X-ray emission

“…Parametric X-ray radiation (PXR) is a well known mechanism of radiation from charged particles propagating in a periodic medium [1][2][3][4][5][6][7][8]. Its qualitative properties are the emission of quasi-monochromatic X-ray beams under the large angle to the electron velocity and the possibility to continuously tune the frequency of the radiation by simply rotating a crystal.…”