Artem Vukolov

Observation of soft X-ray Cherenkov radiation in Al

The soft X-ray radiation generated by 5.7 MeV electrons from both an Al foil and a Mylar film in forward direction was experimentally studied. A narrow specific directivity, an ultra-narrow spectral bandwidth and a good consistency between the experiment and theory prove that the Cherenkov radiation (CR) with photon energy near the L-edge of absorption in Al was observed. The results demonstrate that the CR spectral-angular properties and the absolute photon yield can be described well enough using Pafomovs theoretical model and Henkes refractive index database, which is essential for all practical applications.

Influence of temperature gradient on diffracted X-ray spectrum in quartz crystal

In this work characteristics of hard X-ray (with energy higher than 30 keV) were investigated. In the experiment we measured spectra of X-ray reflected by a quartz monocrystal in Laue geometry under influence of the temperature gradient. The measurements were made by the spectrometer BDER-KI-11K with 300 eV resolution on the 17.74 keV spectral line of Am241 and the spectrometer XR-100CR with 270 eV resolution on the same spectral line. An existence of temperature gradient leads to increasing of the diffracted beam intensity. The intensity was measured dependently on the temperature of one of the edge of the crystal.

Investigation of the characteristics of EUV backward transition radiation generated by 5.7 MeV electrons in mono- and multilayer targets

This paper presents experimental results of a study of radiation in the vacuum ultraviolet and extreme ultraviolet spectral region, generated by electrons with an energy of 5.7 MeV in a multilayer X-ray mirror. The angular distribution of the radiation generated in the rear hemisphere from the input surface of the target was measured. The contribution to the radiation yield caused by the periodic structure of the multilayer target was experimentally investigated.

Observation of quasimonochromatic radiation in the vacuum ultraviolet region generated by 5.7-MeV electrons in a multilayer mirror

Angular distributions of radiation in the vacuum ultraviolet region with a photon energy of about 70 eV, which have been measured for several angles of incidence of 5.7-MeV electrons on the surface of a periodic Mo/Si nanostructure of a multilayer mirror, have been analyzed. It has been shown experimentally that vacuum ultraviolet radiation in the direction of backward transition radiation has a quasimonochromatic component associated with coherent radiation of the periodic structure of the target.

Monochromatization of high-current nanosecond pulse source of x-ray bremsstrahlung

The bremsstrahlung spectrum of the nanosecond electron accelerator on the basis of the vacuum diode supplied by the high-voltage nanosecond generator SINUS - 150 with the coaxial forming line combined with the transformer has been monochromatized by the tungsten crystal under the Bragg - geometry (θB = 450). The dose field map has been taken by the dosimeter on the basis of the diamond detector in the median acceleration plane. The bremsstrahlung radiation beam divergence has left 62°. It has been shown that the maximum dose is 16 cGrey/s at the distance of 10 cm from the collector, then it falls down proportionally to the square of distance to the level less than 0.1 cGrey/s at the distance of 1 m. The X-Ray spectrum has been measured by the silicon semi-conductor X-ray spectrometer with energy resolution 280 eV for 5.9 keV. It has been shown that the two maximum at the spectrum corresponds the second and third orders of diffraction on (111) planes of a tungsten crystal.