Measuring coherent peaks of polarization bremsstrahlung from relativistic electrons in polycrystalline targets in backscattering geometry

Abstract

The spectra of polarization bremsstrahlung (PB) in the X- ray range induced by 7- MeV electrons in a polycrystalline copper target have been measured in the backscattering geometry for various orientations of the target relative to the electron beam. It is shown that the PB backscattering is sensitive to the texture of a target. The possibility of developing a new method based on the measurement of characteristics of the coherent PB component for the diagnostics of polycrystalline materials is consideredyesBelgorod State Universit

Evolution of the characteristics of Parametric X-ray Radiation from textured polycrystals under different observation angles

“…This behavior coincides qualitatively with the theoretical predictions of [18]. In previous works, this theory was partially validated for an isolated observation angle -π [19,21] but a dynamical approval was not performed and the evolution of the PXR characteristics was not observed.…”

Diagnostics of nanodisperse polycrystals based on the polarization bremsstrahlung of relativistic electrons

“…The presence of the characteristic radiation peaks interferes with the PB spectrum measurements near these energy values within the limits of the detector energy resolution. Previously obtained results [5][6][7][8] showed the significant contribution of the escape peak to the measured spectrum of the PB signal. The escape peak is a phantom peak presented in the measured spectrum and formed as a result of the inelastic scat tering of photons recorded by the Si detector.…”

“…The electron beam was transported to the target 7 which was fixed into the vacuum cham ber 6 by means of three rotating magnets 4, two pairs of magnetic quadrupole lenses 5, and a corrector 6, which made it possible to focus the electron beam on the place where the target was located with a size of up to 3 mm and with a divergence of, at most, 5 mrad. These values satisfied the PB measurement conditions in the backscattering geometry, which were limited by the dimensions of the transverse cross section of the electron beam and its divergence [7][8][9]. The trans verse size, the position in the vacuum channel, and the current of the electron beam were controlled by the proportional chamber 11 and a Faraday cylinder 12.…”

“…The potential advantages of the approach under discussion include precise knowledge of the spectrum of pseudophotons of the Coulomb field of fast electrons (the pseudopho tons play the role of the primary probe radiation), which is required within the framework of the energydispersion technique, and also the possibility of obtaining high spatial-measurement resolution because of the simple magnetic focusing of an electron beam on a target [4]. The authors of [9] showed that it is possible to significantly increase the energy resolu tion of measurements in the scheme of BP peak recording in the direction opposite to the velocity of radiating electrons, and the authors of [7] were the first to reliably record this effect. The authors of [8] showed that it is possible to measure the BP signal in the backscattering geometry under the condition that the poly crystal grain size is smaller than the length of BP signal photoabsorption, which emphasized that the developed method for studying polycrystals with submicron grain size is well-grounded.An important problem determin ing the possibility of the use of PB as a new method for studying the atomic structures of polycrystalline media is measurement of the PB signal generated in polycrys tals with a coherent-scattering-region size on the order of 10 nm.…”

“…The polarization bremsstrahlung (PB) of relativis tic electrons [1,2] can be used for the structure diag nostics of polycrystalline media on the basis of the energy-dispersion technique [3][4][5][6][7][8]. The potential advantages of the approach under discussion include precise knowledge of the spectrum of pseudophotons of the Coulomb field of fast electrons (the pseudopho tons play the role of the primary probe radiation), which is required within the framework of the energydispersion technique, and also the possibility of obtaining high spatial-measurement resolution because of the simple magnetic focusing of an electron beam on a target [4].…”