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Vol 43, No 10 (2016)
- Year: 2016
- Articles: 7
- URL: https://journals.rcsi.science/1068-3356/issue/view/14076
Article
Determination of the reflectivity curve of a spherically bent mica crystal used to diagnose X-ray radiation of relativistic laser plasma
Abstract
A method for determining the crystal reflectivity curve, based on the use of a broadband X-ray source and an additional spectrometer with preliminarily measured characteristics is proposed. Such a technique does not allow determination of the absolute reflectivity, but makes it possible to measure the dependence of its relative values on the wavelength. Using X-ray radiation of relativistic dense laser plasma, the reflection curve of a spherically bent mica crystal is measured in the range of 6.7–8.7 Å. The obtained reflectivity curve is used to correctly interpret X-ray spectra of dense plasma generated during the interaction a petawatt laser pulse with solid targets.
291-294
Study of characteristics of the “shashlik” type cellular electromagnetic calorimeter prototype
Abstract
The results of measurements of nonuniformities of the response of heterogeneous cellular electromagnetic calorimeter prototypes are presented. The features of technology solutions used in developing calorimetric modules under study are presented.
295-297
Results of measurements of the atmospheric muon flux in the zenith angle range of 85°–95°
Abstract
The results of the study of the near-horizontal muon flux in the zenith angle range of 85–95 degrees are presented. In particular, the so-called albedo muons (atmospheric muons backscattered in the ground to the upper hemisphere are recorded in this range. The data of measurement series performed at the NEVOD-DECOR experimental complex are analyzed for 30 thousand of “live” time hours. Multiple Coulomb scattering of muons in the ground is simulated by theMonte-Carlo method using various models. The measured muon flux intensity is compared with the simulation results.
298-301
Thermal conductivity of Pb-Mg-Zr alloys and the thermal resistance of the interface between alloys and EP-823 steel in the temperature range of 300–900°C
Abstract
A technique for measuring the thermal resistance of the liquid metal–structural steel interface is proposed. The results ofmeasurements of the thermal resistance of the interface between Pb-Mg-Zr alloys and EP-823 steel and the thermal conductivity of Pb-Mg-Zr alloys in the temperature range of 350–900 °C are presented.
302-305
Application of texture analysis methods to computer microscopy in the visible range of electromagnetic radiation
Abstract
The application of the textural analysis methods based on computer microscopy in the visible region of electromagnetic radiation to classify blood cells into lymphoblasts and lymphocytes is considered. The model of digital processing of cell images is proposed. To quantitatively describe cells in diagnostics and differential diagnostics of acute lymphoblastic leucoses (ALLs), textural characteristics of nucleus images with estimation of their parameters are used.
306-308
Search for solar neutrons using the data of neutron detector of the PAMELA spectrometer
Abstract
The study is devoted to the development of the technique for searching for neutrons of solar origin during solar flares using the neutron detector of the PAMELA magnetic spectrometer onboard the RESURS-DK1 satellite. The study of the neutron detector counting rates showed that it operates properly and background conditions are stable in the geomagnetic equator region. 27 solar events from December 2006 to September 2014 were analyzed. Some events contain indications of solar neutron detection. The final conclusion on the nature of these neutrons requires an increase in statistics; to this end, background conditions in polar regions should be analyzed to increase the observation interval.
309-312
The study of radiation degradation of optical properties of non-stoichiometric Lu3.01−xYxAl4.99O12 crystals doped with Ce3+, Cr3+, and Sc3+ ions under the action of gamma radiation
Abstract
The spectra of pulsed cathodoluminescence (PCL) and optical transmission (OT) of crystals grown from Lu3.01−xYxAl4.99O12 melts doped with Cr3+, Ce3+, and Sc3+ ions before and after irradiation with gamma radiation of a 60Co radioactive source are studied. The gamma radiation dose absorbed by samples was 45 Mrad. The maximum gamma-radiation-induced absorbance in the range of 525–700 nm was 0.48 cm−1. Changes in the PCL and OT spectra of all samples after irradiation were detected. It was found that the relative intensity of Cr3+ bands increased after irradiation in relation to the Ce3+ band intensity by a factor of 1.6–8; the OT spectra of all samples after irradiation lost specific features and became identical. The results obtained are qualitatively explained. According to the explanation, the induced absorption is controlled first of all by optically active Frenkel defects formed after irradiation, which include an oxygen vacancy and an interstitial oxygen ion.
313-318