190 research outputs found

    A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

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    The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the 100MeV\sim 100 \mathrm{MeV} to 1TeV1 \mathrm{TeV} range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected 10810^8 cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary π\pi^- and μ\mu^- emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor stylistic and grammer change

    Protons in near earth orbit

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    The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

    Search for antihelium in cosmic rays

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    The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance and Operation of the CMS Electromagnetic Calorimeter

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    The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

    Внедрение и принцип работы системы сейсмического мониторинга горного массива для работы в условиях ООО "Шахта "Усковская"

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    The status of the Silicon Microvertex Detector (SMD) and its installation into the LEP-L3 experiment are presented, highlighting novel features and sophisticated techniques. Preliminary results based on 1993 data are given and compared with Monte Carlo predictions, to understand the detector performances and its tracking capabilities

    Создание программного обеспечения для проектирования и расчета ректификационных колонн

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    В работе описаны разработанные и программно реализованные методики и алгоритмы расчета технологических и конструкционных параметров тарельчатых и насадочных ректификационных колонн для разделения двух, многокомпонентных и изотопных смесей. Представлены результаты их верификации. Показана хорошая сходимость результатов расчета с известными литературными данными.This work describes the developed and software implemented methods and algorithms for calculating the technological and design parameters of disc-shaped and packed distillation columns for separating two, multicomponent and isotopic mixtures. The results of the verification of the methods are presented. A good convergence of the calculation results with the known literature data is shown

    Ponte et stratégie de la reproduction chez les femelles du tacaud Trisopterus luscus (Gadidés) du plateau continental de la Galice, nord-ouest de l'Espagne

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    [EN] Pouting, Trisopterus luscus is harvested commercially on the Galician shelf by the Spanish inshore artisanal fleet. In spite of a substantial decrease in pouting catches, fishery regulations are limited to size length restrictions. This study provides biological data including length-at-maturity based on histological methods, seasonal maturation, spawning and fecundity. A collection 443 females, from 17 to 42 cm in total length, were sampled from landings (December 2003 to December 2004). Pouting length-at-maturity was estimated as 19.2 cm on average. Pouting females in spawning condition were observed throughout the year and the number of developing oocytes ranged from 20 000 to 1 327 000. Peak spawning was observed between February and April, which correlated well with trends in gonadosomatic index, and inverse to condition factor and hepatosomatic index. Histological examination of the gonads revealed that pouting ovarian development organization is asynchronous, and fecundity is probably determinate.[FR] Le tacaud, Trisopterus luscus est pêché par la flotte artisanale espagnole. En dépit d'une diminution substantielle des captures de tacaud, la pêche est réglementée uniquement à partir d'une taille minimum commerciale. Cette étude fournit des données biologiques comprenant la taille à maturité sexuelle basée sur l'histologie, la maturation saisonnière, la ponte et la fécondité. Un échantillon de 443 femelles, de 17 à 42 cm longueur totale, est examiné à partir des débarquements durant une année (de décembre 2003 à décembre 2004). La taille moyenne à maturité sexuelle est estimée à 19,2 cm. Les femelles de tacaud en condition de ponte sont observée tout au long de l'année et le nombre d'ovocytes s'étend de 20 000 to 1 327 000 par individu. Les pics de ponte sont observés entre février et avril, ce qui est bien corrélé avec l'évolution du rapport gonado-somatique et inverse de celle du facteur de condition et du rapport hépato-somatique. L'étude histologique révèle que le développement ovarien chez le tacaud est asynchrone, et que la fécondité est probablement déterminée.Peer reviewe

    Получение фильтровального материала для очистки воды от Escherichia coli и изучение его свойств

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    An upgrade of the L3 central tracking system, a silicon muvertex detector (SMD), is described. The detector consists of two layers of silicon, each equipped for rφ and z readout with resolution ≈ 6 μm and ≈ 20 μm respectively. The SMD will provide full azimuthal coverage over the polar angular range 22°≤θ≤158°. The total thickness is ≈0.9% of one radiation length
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