Gamma-ray detector based on high pressure xenon for radiation and environmental safety

Gamma-spectrometers based on compressed xenon gas assigned for monitoring the reactors and the radiation background at nuclear power plants, non-proliferation of radioactive materials, supervision and control over the radiation background in the environmentally disadvantaged areas, and other applications, are very promising detectors with excellent performance characteristics. This article reports on the results of the first stage of work on the creation of the portable γ-spectrometer based on compressed xenon that is unique for Ukraine. In order to work with ultra-pure gases under pressure, the complex cryogenic installation for Xe purification and detector filling was designed and manufactured. The installation was made of specially cleaned components, equipped with a heating system for the degassing of the inner walls, and is able of maintaining high vacuum down to 2∙10⁻⁹ mbar. A prototype ionization chamber for the use in portable HPXe detectors was developed and made. For the detector testing, a spectrometric channel based on high-quality electronic components was designed and manufactured. In the initial experiments, a study of the properties of the purified Xe mixed with the dopant H₂ was carried out. The assessment of the lifetime of charge carriers τ in the working gas at a pressure of 30 bar gave the value of τ > 150 μs.Гамма-спектрометри на основі стисненого газу ксенону, що призначені для спостереження і контролю за реакторами і навколишнім фоном на АЕС, нерозповсюдженням радіоактивних матеріалів, радіаційним фоном в екологічно несприятливих зонах і інших застосувань, є дуже перспективними детекторами з відмінними експлуатаційними характеристиками. Дана стаття присвячена результатам першої стадії роботи по створенню унікального для України переносного γ-спектрометра на основі стисненого ксенону. Для роботи з чистими газами під тиском розроблена і виготовлена комплексна кріогенна установка очищення і напуску Xe. Установка створена на основі особливо чистих комплектуючих, оснащена системою прогріву для дегазації внутрішніх стінок і здатна підтримувати високий вакуум до 2∙10⁻⁹ мбар. Розроблено та виготовлено прототип іонізаційний камери для використання в переносних HPXe-детекторах. Для роботи детекторів розроблений і виготовлений спектрометричний тракт на основі високоякісних електронних блоків. В якості перших випробувань проведені дослідження властивостей суміші очищеного Хе з легуючою домішкою H₂. При оцінці часу життя носіїв заряду τ в робочому газі під тиском 30 бар отримані значення τ > 150 мкс.Гамма-спектрометры на основе сжатого газа ксенона, предназначенные для наблюдения и контроля за реакторами и окружающим фоном на АЭС, нераспространением радиоактивных материалов, радиационным фоном в экологически неблагоприятных зонах и других применений, являются очень перспективными детекторами с отличными эксплуатационными характеристиками. Данная статья посвящена результатам первой стадии работы по созданию уникального для Украины переносного γ-спектрометра на основе сжатого ксенона. Для работы с чистыми газами под давлением разработана и изготовлена комплексная криогенная установка очистки и напуска Xe. Установка создана на основе особо чистых комплектующих, оснащена системой прогрева для дегазации внутренних стенок и способна поддерживать высокий вакуум до 2∙10⁻⁹ мбар. Разработан и изготовлен прототип ионизационной камеры для использования в переносных HPXe-детекторах. Для работы детекторов разработан и изготовлен спектрометрический тракт на основе высококачественных электронных блоков. В качестве первых испытаний проведены исследования свойств смеси очищенного Хе с легирующей добавкой H₂. При оценке времени жизни носителей заряда τ в рабочем газе под давлением 30 бар получены значения τ > 150 мкс

Spin light of electron in dense matter

We derive the modified Dirac equation for an electron undergos an influence of the standard model interaction with the nuclear matter. The exact solutions for this equation and the electron energy spectrum in matter are obtained. This establishes a rather powerful method for investigation of different processes that can appear when electrons propagate in background matter. On this basis we study in detail the spin light of electron in nuclear matter, a new type of electromagnetic radiation which can be emitted by an electron moving in dense matter.Comment: 11 pages in LaTex, 4 figures, typos correcte

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Search for the Xb and other hidden-beauty states in the π+π−ϒ(1S) channel at ATLAS

This Letter presents a search for a hidden-beauty counterpart of the X(3872) in the mass ranges of 10.05–10.31 GeV and 10.40–11.00 GeV, in the channel Xb→π+π−ϒ(1S)(→μ+μ−), using 16.2 fb−1 of pp   collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the Xb cross section and branching fraction, relative to those of the ϒ(2S), at the 95% confidence level using the CLS approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the ϒ(13DJ), , and states also reveal no significant signals

Design of tower type structures to dynamic effects taking into account flexibility of the pile foundation and the base

The necessity to take into account flexibility of pile foundation in design of such structures as towers for mobile communication or radio equipment especially under dynamic loads (seismic, fluctuating component of wind load and the resonant vortex excitation) has been considered. The specific features of modeling of pile ductility, using program complex SCAD, were discussed and examples of corresponding calculations are given. The influence of pile parameters on internal forces and deflections of structure were also discussed. It was found, that for screw piles in the calculation results are mostly influenced by diameter of the broadening; the influence of trunk diameter of piles is considerably less. The effect of trunk pile diameter is much more important for piles without the broadening than for screw piles. It was also found that in most cases the effect of pile ductility in the vertical direction is much more significant than in horizontal

Influence of arsenic on grain boundary migration of austenite alloyed with manganese

Translated from Izv. Vyssh. Uchebn. Zaved., Chern. Metall. (1980) (pt.4) p. 113-116SIGLELD:5828.4F(M--26196) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Investigation of process of simultaneous cyclic deformation of various steels in the forging temperature range

22.00; Translated from Russian (Izv. Vyssh. Uchebn. Zaved., Chern. Metall. 1987 (11) p. 74-77)Available from British Library Document Supply Centre- DSC:9022.06(BISI-Trans--26583)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo