The angular resolution of air shower gamma ray telescopes

A crucial charactristic of air shower arrays in the field of high energy gamma-ray astronomy is their angular resolving power, the arrival directions being obtained by the time of flight measurements. A small air shower array-telescope is used to study the resolution in the definition of the shower front as a function of the shower size

Experimental results on gamma-ray sources at E sub 0 = 10(13) - 10(14) eV

The detection of very high energy gamma ray sources has been reported in the last few years by means of extensive air shower observations. The Plateau Rosa array for the registration of the arrival directions of extensive air showers has been operating since 1980 and first results on Cygnus X-3 have been reported. Here, the status of observations of Cygnus X-3 and of the Crab Pulsar are reported

Detection of the primary scintillation light from dense Ar, Kr and Xe with novel photosensitive gaseous detectors

The detection of primary scintillation light in combination with the charge or secondary scintillation signals is an efficient technique to determine the events t=0 as well as particle / photon separation in large mass TPC detectors filled with noble gases and/or condensed noble gases. The aim of this work is to demonstrate that costly photo-multipliers could be replaced by cheap novel photosensitive gaseous detectors: wire counters, GEMs or glass capillary tubes coupled with CsI photocathodes. We have performed systematic measurements with Ar, Kr and Xe gas at pressures in the range of 1-50 atm as well as some preliminary measurements with liquid Xe and liquid Ar. With the gaseous detectors we succeeded in detecting scintillation light produced by 22 keV X-rays with an efficiency of close to 100%. We also detected the scintillation light produced by bs (5 keV deposit energy) with an efficiency close to 25%. Successful detection of scintillation from 22 keV gammas open new experimental possibilities not only for nTOF and ICARUS experiments, but also in others, like WIMPs search through nuclear recoil emission

Quality assurance for CMS Tracker LV and HV Power Supplies

This work describes the quality assurance measurements that have been carried out on about 2000 Power Supply Units produced in CAEN technology for the CMS Silicon Tracker Detector. The automate procedure and the characteristics of the dedicated Test Fixture developed for this activity are described in details. Magnetic field tolerance and radiation hardness of Tracker power supply units is also discussed at length

Beyond the RICH: Innovative Photosensitive Gaseous Detectors for new Fields of Applications

We have developed and successfully used several innovative designs of detectors with solid photocathodes. The main advantage of these detectors is that rather high gains (>10E4) can be achieved in a single multiplication step. This is possible by, for instance, exploiting the secondary electron multiplication and limiting the energy of the steamers by distributed resistivity. The single step approach also allows a very good position resolution to be achieved in some devices: 50 micron on line without applying any treatment method (like center of gravity). The main focus of our report is new fields of applications for these detectors and the optimization of their designs for such purposes.Comment: 14 pages, 7 figures, 3 table

ArDM: first results from underground commissioning

The Argon Dark Matter experiment is a ton-scale double phase argon Time Projection Chamber designed for direct Dark Matter searches. It combines the detection of scintillation light together with the ionisation charge in order to discriminate the background (electron recoils) from the WIMP signals (nuclear recoils). After a successful operation on surface at CERN, the detector was recently installed in the underground Laboratorio Subterr\'aneo de Canfranc, and the commissioning phase is ongoing. We describe the status of the installation and present first results from data collected underground with the detector filled with gas argon at room temperature.Comment: 6 pages, 3 figures, Light Detection In Noble Elements (LIDINE 2013

Status of the ArDM Experiment: First results from gaseous argon operation in deep underground environment

The Argon Dark Matter (ArDM-1t) experiment is a ton-scale liquid argon (LAr) double-phase time projection chamber designed for direct Dark Matter searches. Such a device allows to explore the low energy frontier in LAr. After successful operation on surface at CERN, the detector has been deployed underground and is presently commissioned at the Canfranc Underground Laboratory (LSC). In this paper, we describe the status of the installation and present first results on data collected in gas phase.Comment: 21 pages, 20 figure

First observation of Cherenkov rings with a large area CsI-TGEM-based RICH prototype

We have built a RICH detector prototype consisting of a liquid C6F14 radiator and six triple Thick Gaseous Electron Multipliers (TGEMs), each of them having an active area of 10x10 cm2. One triple TGEM has been placed behind the liquid radiator in order to detect the beam particles, whereas the other five have been positioned around the central one at a distance to collect the Cherenkov photons. The upstream electrode of each of the TGEM stacks has been coated with a 0.4 micron thick CsI layer. In this paper, we will present the results from a series of laboratory tests with this prototype carried out using UV light, 6 keV photons from 55Fe and electrons from 90Sr as well as recent results of tests with a beam of charged pions where for the first time Cherenkov Ring images have been successfully recorded with TGEM photodetectors. The achieved results prove the feasibility of building a large area Cherenkov detector consisting of a matrix of TGEMs.Comment: Presented at the International Conference NDIP-11, Lyon,July201