Using mosaic crystals for the generation of intense X-ray beams

The parametric X-ray (PXR) yield due to 500-MeV electrons in a 2-mm-thick diamond crystal with a mosaicity angle of ~0.2 mrad has been studied. It is shown that the mosaic crystal structure leads to a significant (about fourfold) increase in the PXR yield doe to the contribution of diffracted bremsstrahlung radiationye

Experimental observation of parametric X-ray radiation directed along the propagation velocity of relativistic electrons in a tungsten crystal

Parametric X-ray radiation (PXR) due to dynamic diffraction of relativistic electrons is experimentally observed at small angles to the propagation velocity of electrons in a tungsten crystal. The specific features of the experimental method are described, and forward PXR reflections from two crystallographic planes of tungsten are reliably measuredyesBelgorod State Universit

Simulation and optimization of occupant behavior in energy consumption

One of the biggest part of building energy consumption is influenced by human element. Each occupant interacts with systems of his house, work place, etc. in his own way. This paper introduced the potential of following working with optimization of human element and showed possible solutions of reduction negative impact of occupant behavior on energy usage taking into account mental, economical and technologic aspects.Одной из основных статей в энергопотреблении зданий является человеческий фактор. Каждый потребитель электроэнергии по-своему взаимодействует с системами дома и рабочего места. В данном докладе описан потенциал дальнейших работ по оптимизации человеческого фактора, показаны возможные модели по снижению негативного воздействия жильца на энергозатраты, с учётом ментальных особенностей, экономического, психологического и технологического аспектов

Enabling comparison of UrQMD with Geant4 hadronic models

Geant4 has an abundant set of physics models that handle the diverse interaction of particles with matter across a wide energy range. However, there are also many well established reaction codes currently used in the same fields where Geant4 is applied. One such code is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. In order to take advantage of the UrQMD code, we create a tool to enable comparisons among UrQMD and Geant4 hadronic models. This tool allows a user to process the output file of UrQMD through Geant4 toolkit, while at the same time, can choose among different Geant4 hadronic model generators. As an example, the UrQMD model is compared with the HARP-CDP experimental data and with the Binary and FRITIOF generators, in the framework of Geant4. It is shown that the UrQMD model can better reproduce charged pion production for p+Cu and Pb interactions at 3, 8 and 15 GeV/c, and is a good candidate for Geant4 hadronic models.Comment: 17 pages, 5 Figure

Subthreshold and near-threshold kaon and antikaon production in proton-nucleus reactions

The differential production cross sections of K^+ and K^- mesons have been measured at the ITEP proton synchrotron in p+Be, p+Cu collisions under lab angle of 10.5^0, respectively, at 1.7 and 2.25, 2.4 GeV beam energies. A detailed comparison of these data with the results of calculations within an appropriate folding model for incoherent primary proton-nucleon, secondary pion-nucleon kaon and antikaon production processes and processes associated with the creation of antikaons via the decay of intermediate phi mesons is given. We show that the strangeness exchange process YN->NNK^- gives a small contribution to the antikaon yield in the kinematics of the performed experiment. We argue that in the case when antikaon production processes are dominated by the channels with KK^- in the final state, the cross sections of the corresponding reactions are weakly influenced by the in-medium kaon and antikaon mean fields.Comment: 24 pages. accepted for publication at J.Phys.

On the evaporation dynamics of trinitrotoluene microparticles on the glass surface

The results of measuring the time dependence of the concentration of trinitrotoluene (TNT) vapor over its solid microconcentrations on the glass surface with a low TNT concentration on the surface of 100 ng/cm2 are presented. Such microconcentrations of traces are typical for the conditions of anti-terrorist control of objects for the presence of TNT. The measurements were made using a portable multicapillary gas chromatograph (GC) EKHO-V-IDTS (Russia) with TNT vapor concentration. The threshold for determining the concentration of TNT vapor by the EKHO-V-IDTS gas chromatograph corresponds to the modern level and is equal to 10-14 g/cm3. Vapor sampling is performed by a vortex sampling device (VSD), which is used in the anti-terrorist control of objects. It is shown that the initial surface concentration of TNT traces of 100 ng/cm2 on the glass surface decreases to 12 ng/cm2 in a time of 2.6 h due to evaporation into an open half-space under laboratory conditions. The vapor concentration over the residual TNT concentration of 12 ng/cm2 corresponds to the GC sensitivity threshold for TNT vapor concentration equal to 10-14 g/cm3

Clustering in light nuclei in fragmentation above 1 A GeV

The relativistic invariant approach is applied to analyzing the 3.3 A GeV $^{22}$Ne fragmentation in a nuclear track emulsion. New results on few-body dissociations have been obtained from the emulsion exposures to 2.1 A GeV $^{14}$N and 1.2 A GeV $^{9}$Be nuclei. It can be asserted that the use of the invariant approach is an effective means of obtaining conclusions about the behavior of systems involving a few He nuclei at a relative energy close to 1 MeV per nucleon. The first observations of fragmentation of 1.2 A GeV $^{8}$B and $^{9}$C nuclei in emulsion are described. The presented results allow one to justify the development of few-body aspects of nuclear astrophysics.Comment: 7 pages, 8 figures, 3 tables, Nuclear Physics in Astrophysics-2, 16-20 May, 2005 (ATOMKI), Debrecen, Hungar

ВВОД ПРОБЫ АРОМАТИЧЕСКИХ СОЕДИНЕНИЙ С КОНЦЕНТРАТОРОВ В ПОЛИКАПИЛЛЯРНУЮ КОЛОНКУ МЕТОДОМ ТЕРМИЧЕСКОЙ ДЕСОРБЦИИ

At present, there is an increased interest in geochemical methods of searching for hydrocarbon deposits by detecting on the Earth's surface the scattering halos of hydrocarbons that migrated from those deposits, namely the aromatic hydrocarbons such as benzene, toluene, xylenes. The concentrations of the migrated hydrocarbons on the surface of the Earth are usually low and could only be detected at the threshold level of the gas analyzers. Therefore, for their registration, the preconcentration is applied, in particular, the passive preconcentration. For this purpose, the concentrators are used, which are laid at shallow depths in the explored area. The survey technology that is being developed by the authors uses the reusable concentrators in the form of hollow stainless-steel tubes with SE-30 siloxane-based sorbent applied on their inner surface. The concentrators placed in the analytical containers are laid in the ground for 1-2 days. The analysis of the samples from the concentrators is carried out on a portable multicapillary gas chromatograph in the field conditions. The current article is devoted to the development of a special device for the sample injection from the passive concentrators and the experimental determination of the optimal mode of thermal desorption sample injection from the concentrators into the multicapillary column. The original injection scheme is given, where the gas-dynamic isolation of the injection device camera and the multicapillary column during the concentrator heating and sample analysis is implemented; the optimum concentrator heating time and the optimum sample injection time are determined.Keywords: passive concentrators, thermal desorption sample injection, gas-dynamic isolation of the injection device and columnDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.003(Russian)V.M. Gruznov1,2,3, M.N. Baldin1, A.O. Malysheva1,3 1Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch of Russian Academy of Sciences, Koptug Avenue, 3, Novosibirsk, 630090,Russian Federation2Novosibirsk State University, Pirogova St., 2, Novosibirsk, 630090, Russian Federation3Novosibirsk State Technical University, Prospekt K. Marx Avenue, 20, Novosibirsk, 630073, Russian FederationВ настоящее время возрос интерес к геохимическим методам поиска залежей углеводородов по выявлению на поверхности Земли ореолов углеводородов, мигрирующих из залежей, в частности ароматических углеводородов: бензола, толуола, ксилолов. Концентрации мигрирующих углеводородов на поверхности Земли, как правило низкие, и находятся на уровне пороговых значений для газоаналитических приборов. Поэтому для их регистрации применяют концентрирование, в частности пассивное. Для этого используют концентраторы, закладываемые на небольшие глубины на разведываемой площади. В технологии съёмки, разрабатываемой авторами, используются многоразовые концентраторы в виде полых трубок из нержавеющей стали с сорбентом на основе силоксана SE-30, нанесенного на внутреннюю поверхность. Концентраторы в аналитических контейнерах закладываются в грунт на 1-2 суток. Анализ проб с концентраторов осуществляется на портативном поликапиллярном газовом хроматографе в полевых условиях. Статья посвящена специальному устройству ввода пробы с пассивных концентраторов и экспериментальному определению оптимального режима термодесорбционного ввода пробы с концентраторов в поликапиллярную колонку. Приведена оригинальная схема ввода, в которой реализована газодинамическая изоляция камеры устройства ввода и поликапиллярной колонки во время нагрева концентратора и анализа пробы, определено оптимальное время нагревания концентраторов и время ввода пробы.Ключевые слова: пассивные концентраторы, ввод методом термической десорбции, газодинамическая изоляция устройства ввода и колонкиDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.00