Full depletion voltage and separation voltage for a double-sided microstrip detector

The results of investigation of the full depletion and separation voltages are presented. It is shown that these voltages do not always have similar values. The explanation of this effect is suggested.Представлены результаты исследования напряжения полного обеднения и напряжения разделения. Показано, что эти напряжения не всегда имеют близкие величины. Предложено объяснение этого эффекта.Представлені результати дослідження напруги повного збіднення и напруги розділення. Показано, що ці напруги не завжди мають значення яки е близькими. Запропоновано пояснення цього явища

Magnetizing of Finemet-type alloys by magnetization rotation in weak fields

Magnetic properties of functional magnetic materials depend on the magnetization processes nature. Creation of amorphous and nanocrystalline alloys using the rapid quenching technology is the result of the latest advances in magnetic materials area. Although significantly different in structure, they show excellence properties. In this paper we will investigate the magnetization properties of the Finemet-type nanocrystalline alloys in the range of their initial permeability formation. We will show that due to low level of effective magnetic anisotropy, even in weak fields, magnetization can occur through reversible, hysteresis-free rotation of the domain's magnetization vector. © Published under licence by IOP Publishing Ltd.Ministry of Science and Higher Education of the Russian Federation: 3.6121.2017/8.9, 4.9541.2017/8.9This work was supported by the Ministry of Science and higher Education and of the Russian Federation in the framework of state tasks No. 3.6121.2017/8.9 and No. 4.9541.2017/8.9

A Method for Magma Viscosity Assessment by Lava Dome Morphology

Lava domes form when a highly viscous magma erupts on the surface. Several types of lava dome morphology can be distinguished depending on the flow rate and the rheology of magma: obelisks, lava lobes, and endogenic structures. The viscosity of magma nonlinearly depends on the volume fraction of crystals and temperature. Here we present an approach to magma viscosity estimation based on a comparison of observed and simulated morphological forms of lava domes. We consider a two-dimensional axisymmetric model of magma extrusion on the surface and lava dome evolution, and assume that the lava viscosity depends only on the volume fraction of crystals. The crystallization is associated with a growth of the liquidus temperature due to the volatile loss from the magma, and it is determined by the characteristic time of crystal content growth (CCGT) and the discharge rate. Lava domes are modeled using a finite-volume method implemented in Ansys Fluent software for various CCGTs and volcanic vent sizes. For a selected eruption duration a set of morphological shapes of domes (shapes of the interface between lava dome and air) is obtained. Lava dome shapes modeled this way are compared with the observed shape of the lava dome (synthesized in the study by a random modification of one of the calculated shapes). To estimate magma viscosity, the deviation between the observed dome shape and the simulated dome shapes is assessed by three functionals: the symmetric difference, the peak signal-to-noise ratio, and the structural similarity index measure. These functionals are often used in the computer vision and in image processing. Although each functional allows to determine the best fit between the modeled and observed shapes of lava dome, the functional based on the structural similarity index measure performs it better. The viscosity of the observed dome can be then approximated by the viscosity of the modeled dome, which shape fits best the shape of the observed dome. This approach can be extended to three-dimensional case studies to restore the conditions of natural lava dome growth

EuroGammaS gamma characterisation system for ELI-NP-GBS: The nuclear resonance scattering technique

A Gamma Beam Characterisation System has been designed by the EuroGammaS association for thecommissioning and development of the Extreme Light Infrastructure-Nuclear Physics Gamma Beam System(ELI-NP-GBS) to be installed in Magurele, Romania. The characterisation system consists of four elements: aCompton spectrometer, a sampling calorimeter, a nuclear resonant scattering spectrometer (NRSS) and a beamprofile imager. In this paper, the nuclear resonant scattering spectrometer system, designed to perform anabsolute energy calibration for the gamma beam, will be describe

Free vacuum for loop quantum gravity

We linearize extended ADM-gravity around the flat torus, and use the associated Fock vacuum to construct a state that could play the role of a free vacuum in loop quantum gravity. The state we obtain is an element of the gauge-invariant kinematic Hilbert space and restricted to a cutoff graph, as a natural consequence of the momentum cutoff of the original Fock state. It has the form of a Gaussian superposition of spin networks. We show that the peak of the Gaussian lies at weave-like states and derive a relation between the coloring of the weaves and the cutoff scale. Our analysis indicates that the peak weaves become independent of the cutoff length when the latter is much smaller than the Planck length. By the same method, we also construct multiple-graviton states. We discuss the possible use of these states for deriving a perturbation series in loop quantum gravity.Comment: 30 pages, 3 diagrams, treatment of phase factor adde

Symmetries and observables in topological gravity

After a brief review of topological gravity, we present a superspace approach to this theory. This formulation allows us to recover in a natural manner various known results and to gain some insight into the precise relationship between different approaches to topological gravity. Though the main focus of our work is on the vielbein formalism, we also discuss the metric approach and its relationship with the former formalism.Comment: 34 pages; a few explanations added in subsection 2.2.1, published version of pape

ПОСТРОЕНИЕ ПРОГРАММНО-АППАРАТНОГО КОМПЛЕКСА ДЛЯ ИССЛЕДОВАНИЯ РАСПРЕДЕЛЕНИЯ ЭЛЕКТРОМАГНИТНОГО ПОЛЯ В БЛИЖНЕЙ ЗОНЕ ДИЭЛЕКТРИЧЕСКИХ И МЕТАЛЛИЧЕСКИХ НАНОЧАСТИЦ

The results of research and development of high-performance hardware and software computer system for modeling the distribution of electromagnetic fields in the near field of metallic and dielectric nanoparticles of the analyzed. The complex is based on free software. The calculation results of the analytical and numerical values of electromagnetic fields in the vicinity of spherical nanoparticles are shown for comparison.Приведены результаты разработки и исследования созданного на основе свободно распространяемого программного обеспечения высокопроизводительного программно-аппаратного вычислительного комплекса для моделирования распределения электромагнитных полей в ближней зоне металлических и диэлектрических наночастиц. В качестве сравнения приведены примеры расчета аналитического и численного значения полей вблизи сферических наночастиц

A Method for Magma Viscosity Assessment by Lava Dome Morphology

Abstract: Lava domes form when a highly viscous magma erupts on the surface. Several types of lava dome morphology can be distinguished depending on the flow rate and the rheology of magma: obelisks, lava lobes, and endogenic structures. The viscosity of magma nonlinearly depends on the volume fraction of crystals and temperature. Here we present an approach to magma viscosity estimation based on a comparison of observed and simulated morphological forms of lava domes. We consider a two-dimensional axisymmetric model of magma extrusion on the surface and lava dome evolution, and assume that the lava viscosity depends only on the volume fraction of crystals. The crystallization is associated with a growth of the liquidus temperature due to the volatile loss from the magma, and it is determined by the characteristic time of crystal content growth (CCGT) and the discharge rate. Lava domes are modeled using a finite-volume method implemented in Ansys Fluent software for various CCGTs and volcanic vent sizes. For a selected eruption duration a set of morphological shapes of domes (shapes of the interface between lava dome and air) is obtained. Lava dome shapes modeled this way are compared with the observed shape of the lava dome (synthesized in the study by a random modification of one of the calculated shapes). To estimate magma viscosity, the deviation between the observed dome shape and the simulated dome shapes is assessed by three functionals: the symmetric difference, the peak signal-to-noise ratio, and the structural similarity index measure. These functionals are often used in the computer vision and in image processing. Although each functional allows to determine the best fit between the modeled and observed shapes of lava dome, the functional based on the structural similarity index measure performs it better. The viscosity of the observed dome can be then approximated by the viscosity of the modeled dome, which shape fits best the shape of the observed dome. This approach can be extended to three-dimensional case studies to restore the conditions of natural lava dome growth. © 2021, The Author(s).We are grateful to two anonymous reviewers for their constructive comments. Numerical experiments were carried out on the Uran computing cluster (Institute of Mathematics and Mechanics, Ural Branch of the Russian Academy of Sciences, Yekaterinburg). The work was supported by the Russian Science Foundation (project no. 19-17-00027)

The Gnevyshev Gap Effect in Galactic Cosmic Rays

Abstract During the last three solar cycles and in a wide energy range of galactic cosmic rays both the modulation and the variability of the intensity demonstrate effects related to the Gnevyshev Gap (GG) -a substantial decrease once or twice during the maximum phase of each solar cycle of a parameter that generally varies in phase with the cycle. The GG-effect also manifests itself in the behaviour of both the strength of the average interplanetary magnetic field and the power of its fluctuating component. The energy dependence of the GGeffect in the modulation and in the variability of the cosmic ray intensity was found to be different. The start of the GG-effect in the cosmic ray modulation practically coincides with a change in the energy dependence of the cosmic ray modulation