The camera of the fifth H.E.S.S. telescope. Part I: System description

In July 2012, as the four ground-based gamma-ray telescopes of the H.E.S.S. (High Energy Stereoscopic System) array reached their tenth year of operation in Khomas Highlands, Namibia, a fifth telescope took its first data as part of the system. This new Cherenkov detector, comprising a 614.5 m^2 reflector with a highly pixelized camera in its focal plane, improves the sensitivity of the current array by a factor two and extends its energy domain down to a few tens of GeV. The present part I of the paper gives a detailed description of the fifth H.E.S.S. telescope's camera, presenting the details of both the hardware and the software, emphasizing the main improvements as compared to previous H.E.S.S. camera technology.Comment: 16 pages, 13 figures, accepted for publication in NIM

Laser monitoring system for the CMS lead tungstate crystal calorimeter

We report on the multiple wavelength laser monitoring system designed for the CMS lead tungstate crystal calorimeter read-out with avalanche photodiodes (Barrel calorimeters) and vacuum phototriodes (End Cap calorimeters). Results are presented for the test beam performance of the system designed to achieve 0.5% relative inter-calibration of the optical transmittance for lead tungstate scintillation emission over nearly 80 000 channels. The system operates in continuous measurement cycles to follow each crystal?s evolution under irradiation and recovery periods foreseen during operation at the LHC

Pharmacological Alterations of Anxious Behaviour in Mice Depending on Both Strain and the Behavioural Situation

A previous study comparing non-emotive mice from the strain C57BL/6/ByJ with ABP/Le mice showed ABP/Le to be more anxious in an open-field situation. In the present study, several compounds affecting anxiety were assayed on ABP/Le and C57BL/6/ByJ mice using three behavioural models of anxiety: the elevated plus-maze, the light-dark discrimination test and the free exploratory paradigm. The compounds used were the full benzodiazepine receptor agonist, chlordiazepoxide, and the antagonist, flumazenil, the GABAA antagonist, bicuculline, the full 5-HT1A agonist 8-OH-DPAT, and the mixed 5-HT1A/5-HT1B agonist, RU 24969. Results showed the effect of the compounds to be dependent on both the strain and the behavioural task. Several compounds found to be anxiolytic in ABP/Le mice had an anxiogenic effect on C57BL/6/ByJ mice. More behavioural changes were observed for ABP/Le in the elevated plus-maze, but the clearest findings for C57BL/6/ByJ mice were observed in the light-dark discrimination apparatus. These data demonstrate that anxious behaviour is a complex phenomenon which cannot be described by a single behavioural task nor by the action of a single compound

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Kinetics of hydrazinium nitrate decomposition in nitric acid solutions under the effect of power ultrasound

International audienc

Behavioral models for anxiety and multisensory integration in animals and humans

cote interne IRCAM: ViaudDelmon10aNone / NoneNational audienceBehavioral models for anxiety and multisensory integration in animals and human

Kinetics of nitrous acid formation in a two-phase tri-n-butylphosphatediluent/aqueous nitric acid extraction system under the effect of power ultrasound

International audienc

Effect of carbon oxides on alpha-radiolysis of water sorbed on plutonium dioxide

International audiencePlutonium dioxide PuO2 is one of the main end-product in nuclear spent fuel reprocessing. This compound is classically stored in sealed containers under more or less moisty atmosphere before its reuse to manufacture new mixed-oxide (MOx) fuel. Plutonium dioxide is a very hygroscopic material and then the water molecules present in the moisty atmosphere are quickly adsorbed on plutonium dioxide surface [1-3]. This sorbed water then undergoes an a-radiolysis due to the plutonium radioactive decay. It has been showed that the decomposition of sorbed water on plutonium dioxide leads to the release of dihydrogen H2 [4-7]. Obviously, the kinetics of hydrogen evolution in the atmosphere depends on several physico-chemical parameters such as the specific surface area and isotopic composition of plutonium dioxide and the relative humidity of the atmosphere.However, the influence of the atmosphere above plutonium dioxide in the containers on dihydrogen generation has not been examined to a large extend. Most of the published data have been obtained under air or inert (Ar) atmosphere. Comparison of the data is not obvious and the effect of O2 and N2 on H2 formation is quite difficult to discern. In our experiments an increase in dihydrogen formation has sometimes been observed under an atmosphere of air compared to an Ar atmosphere, but the opposite effect, a decrease in hydrogen production, has happened too and unfortunately no clear conclusion can be drawn from these observations.Since carbon dioxide CO2 seems to be quickly and widely adsorbed on plutonium dioxide surface [8], it has then been decided to look at the effect of this gaseous compound on the kinetics of dihydrogen release in moisty atmospheres. The analysis has been extended to carbon monoxide and mixture of CO and CO2. The formation of dihydrogen as well as the consumption of carbon oxides has been followed using gas chromatography. The carbon oxides were introduced in the experiment cells at a level amount of 5-10 vol. percent as a mixture with Argon and the relative humidity is kept constant in the cells. It has been observed that the amount of produced dihydrogen slightly increases in the presence of CO2 in comparison of what have been measured under pure argon. In the same time, no measurable consumption of CO2 has been detected. Dihydrogen formation is significantly enhanced in the presence of CO, this latter being oxidized as CO2. The formation of H2 under an atmosphere containing both CO and CO2 is particular: in a first step, the formation of H2 is lowered and in a second step it looks like the one observed in the presence of CO only. Mechanisms have been postulated to account for these phenomena