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[en] Detectors for high-energy physics make use of photomultipliers in a variety of ways. They include high resolution time-of-flight measurements, Cerenkov light detection, precise pulse-height measurements, etc. In particular, the use of large numbers of photomultipliers in total-energy (or ''calorimetry'') detectors requires high stability, reliability and low-cost. This aspect is illustrated by the example of a new large detector built to observe proton-antiproton collisions at very high energies
[fr]Les detecteurs employes en physique de hautes energies utilisent les photomultiplicateurs de differentes facons. On a, par exemple, des mesures de temps de vol a haute resolution, l'observation de lumiere Cerenkov, des mesures de hauteurs d'impulsion de haute precision, etc. En particulier, on utilise des grandes quantites de photomultiplicateurs pour la mesure d'energie totale (dans les ''calorimetres''), ce qui necessite des stabilites et fiabilites tres poussees, et un cout unitaire reduit. Pour illustrer ces aspects, on decrit a titre d'exemple un nouveau grand detecteur destine a observer des collisions protons-antiprotons de tres haute energie
[en] A device to simultaneously measure the radon content of the atmosphere and its decay products associated with the atmospheric aerosols is described. The radon daughters are continuously precipitated through an eletrostatic field onto an alpha particle detector wich is also the collecting electrode. Either total counting or spectral analysis can be obtained as output data. The decay products radon associated to the aerosols are measured in membrane filters after collecting the atmospheric aerosols within a given sampling time interval. The sentivity of the instrument is better than 0.61 pCi.m-3, and the response time to a transient concentration change of radon is better than 20 minutes, in the present configuration. (author)
[pt]Este trabalho apresenta um instrumento desenvolvido especificamente para permitir um estudo quantitativo e simultaneo do gas radonio na atmosfera e de seus produtos de decaimento associados aos aerossois atmosfericos (deposito ativo). O radonio pode ser moniterado continuamente, enquanto o seu deposito ativo medido diretamente em filtros de membrana, apos um intervalo de tempo de coleta que depende da atividade local. (autor)
[en] Conclusion: • Radiation detection must be part of a broader nuclear security strategy. • Architecture should be defined by overall strategy. • Architecture options facilitated by technological developments. • Revolutionary changes in detection have occurred in the past two decades. • Need to reinforce these changes with new technology and craft an Architecture that takes advantage of these technological changes
[en] The aims of this project are to enable rational materials design for select high-payoff challenges in radiation detection materials by using state-of-the-art predictive atomistic modeling techniques. Three specific high-impact challenges are addressed: (i) design and optimization of electrical contact stacks for TlBr detectors to stabilize temporal response at room-temperature; (ii) identification of chemical design principles of host glass materials for large-volume, low-cost, highperformance glass scintillators; and (iii) determination of the electrical impacts of dislocation networks in Cd1-xZnxTe (CZT) that limit its performance and usable single-crystal volume. The specific goals are to establish design and process strategies to achieve improved materials for high performance detectors. Each of the major tasks is discussed below in three sections, which include the goals for the task and a summary of the major results, followed by a listing of publications that contain the full details, including details of the methodologies used. The appendix lists 12 conference presentations given for this project, including 1 invited talk and 1 invited poster.
[en] The research on the composition of the chemical elements in atmosphere and monitoring of industrial and technigenic wastes are of special significance in connection with the possibility connection of gobal environmental pollution. The present paper shows the results of investigation on studies of pollution in radioactivity fallout, in soil at some areas of Ulaanbaatar city, carried out through the gamma activation method and alpha, beta radiometrical analysis at the Nuclear Research Laboratory, the State University (Mongolia). Received results enable us to estimate seasonal, monthly and daily variations of weight concentration and elemental structure in aerosol during the period of investigation. 2 tabs
[en] This project extends the “Enhanced Radiological Nuclear Inspection and Evaluation” (ERNIE) system developed with CBP and DNDO to improve performance of PVT-based Radiation Portal Monitors (RPMs). ERNIE was designed to be used with any RPM system. The first implementation was with the SAIC (Leidos) RPM-8 systems. In this project, we are demonstrating how effective the ERNIE approach can be when applied to the VM250 TSA portals used in NSDD programs. Part of the challenge in adapting ERNIE to handle VM250 portals is the lack of gamma spectral information. We report here on the first results showing how the ERNIE analysis can improve analysis of measurements with the VM250 RPMs.
[en] The recent experiment reporting the discovery of a monopole is compared to the negative experiments performed previously. The different determinations of the flux of monopoles are contradictory. It is likely that the event reported as a monopole may be given another interpretation
[en] Half value layer (radiation energy) of 90deg scattered radiation shielding materials was measured at 1 m distance from the central ray of the primary beam. Scattered radiation was measured from 100 to 200 kVp for 0-2.0mm Cu+1.0mm Al added filter in the primary beam for a deep therapeutic unit, the obtained result results were as follows: 1. The ratio of scattered radiation to primary radiation was increased by the using lighter filter. 2. The ratio of scattered radiation to primary radiation was decreased by using heavier filter. 3. The ratio of scattered radiation to primary radiation was independent of tube voltage. 4. The scattered radiation of high energy was produced, when the effective atomic number and density of shielding material were high. (Author)