Novel radiator for generation of coherent X-rays by relativistic electrons

An experiment with a novel type of a periodic crystalline target for generation of coherent X-rays by relativistic electrons is described. The target has been etched on the surface of a GaAs crystal plate by means of microlithography. The etched microstructure is a system of about 300 stripes 14 /spl mu/m thick, 100 /spl mu/m high and the gaps between the stripes are 29 /spl mu/m. The measured spectra and orientation dependence of the X-rays emitted at an angle of 19/spl deg/ to the 500 MeV electron beam of the Tomsk synchrotron are discussed. The generated 27 keV radiation consists of parametric X-ray radiation (PXR) and diffracted X-ray transition radiation (DTR). It has been shown that the intensity of the DTR component of generated X-rays is much greater than that of the PXR.