Ratio of the contributions real and virtual photons diffraction in thin perfect crystals. Comparison of calculation and experiment

Phys. Rev. Accel. Beams

Laktionova

Shatokhin

et al. 2019

A technique is proposed for determining beam dimensions on a target by measuring two-dimensional angular distributions of the radiation for two distances between the crystal where the radiation is generated and a coordinate detector. The dimensions are determined from the results of a least squares method procedure with varying parameters, where the adjustable function is the distribution for a shorter distance and the fitting function is the convolution of the angular distribution at a greater distance with a twodimensional Gaussian distribution whose parameters are uniquely related to the beam dimensions on the target and the distances between the crystal and the detector. The minimum measured beam sizes are about 50-60 μm for the parametric x-ray mechanism and an electron energy of less than 1 GeV and 10-15 μm for the mechanism of diffracted transition radiation and electrons with an energy above several GeV.

Section: Accounting For the Spatial Dimensions Of The Electron Beammentioning

confidence: 99%

New method of electron beam transverse size measurement by angular distribution of emission in a thin crystal

Phys. Rev. Accel. Beams

Laktionova

Shatokhin

et al. 2019

“…The presence of the bright peak in the angular radiation distribution [16,23], whose form is like that of the angular PXR distribution, in Figs. 1 and 3, makes it possible also to use the above procedure to determine the dimensions of a high-energy electron beam.…”

Section: We Assume Thatmentioning

confidence: 77%

“…Simulation was performed by means of the Monte Carlo method for the parameters of an HR25 detector [22] used in the experiment [8], where a P43 scintillator with the chemical composition Gd 2 SO 2 and a thickness of 30 μm was used. The procedure for simulating the detector parameters was given in [23].…”

Section: We Assume Thatmentioning

confidence: 99%

Proposal for a Procedure for Measuring the Transverse Dimensions of a Beam of Relativistic Electrons with a Small Longitudinal Size

Vnukov

Laktionova

et al. 2020

J. Synch. Investig.

The possibility of implementing a previously proposed procedure for determining the beam dimensions at a target is analyzed; it includes the measurement of two-dimensional angular distributions of the coherent radiation of fast electrons for two distances between a crystal, where radiation is generated, and a coordinate detector. The use of two mechanisms of parametric X-ray radiation and diffracted transition radiation is considered. The limits of the method sensitivity and the influence of the departure of secondary electrons and photons on them are discussed.

“…The target thickness was greater than the characteristic length of photons diffraction process in the crystal ext ≈ 1.87 μm for this reflection order and the photon energy, see Refs. [22,23] and reference therein. The detection system was located 10 m from the crystal at an angle of Θ D = 2Θ B = 90 • .…”

Section: Calculation Results and Discussionmentioning

confidence: 99%

“…This approach allows us to describe the contribution of the diffracted photons, such as bremsstrahlung and TR, in experimentally measured yields of electron emissions at Bragg angles with an error less than 20% [23].…”

Section: Theoretical Considerationsmentioning

confidence: 99%

Diffracted diffraction radiation and its application to beam diagnostics

Nuclear Instruments and Methods in Physics Research Section A:

Shatokhin

Sumitani

et al. 2018

Self Cite

We present theoretical considerations for diffracted diffraction radiation and also propose an application of this process to diagnosing ultra-relativistic electron (positron) beams for the first time. Diffraction radiation is produced when relativistic particles move near a target. If the target is a crystal or X-ray mirror, diffraction radiation in the X-ray region is expected to be diffracted at the Bragg angle and therefore be detectable. We present a scheme for applying this process to measurements of the beam angular spread, and consider how to conduct a proof-of-principle experiment for the proposed method.