[en] GLAST is a space mission that will observe the gamma-ray sky between 20MeV and 1TeV with unprecedented resolution and sensitivity. The Large Area Telescope (LAT), the main instrument onboard the GLAST satellite, is built with state-of-the-art particle physics detectors, and combines a large area is-strip tracker-converter, that will measure direction of incoming photons to an imaging CsI e.m. calorimeter for measurements of photon energies; an outer, segmented Anti-Coincidence Detector will reject charged particle background. In this paper they give an overview of the many physics goals and potential reach of the GLAST observatory and describe in detail the instrument design and performance

[en] The GLAST Large Area Telescope (LAT) is a satellite gamma-ray observatory designed to explore the sky in the energy range 20MeV ≅ 300GeV, a region populated by emissions from the most energetic and mysterious objects in the cosmos, like black holes, AGNs, supernovae, gamma-ray bursters. The silicon-strip tracker is the heart of the photon detection system, and with its 80 m² of surface and almost 1M channels is one of the largest silicon tracker ever built. Its construction, to be completed by 2006, and the stringent requirements from operation in space, represent a major technological challenge. Critical design, technology and system engineering issues are addressed in this paper, as well as the approach being followed during construction, test and qualification of the LAT silicon tracker

[en] The Large Area Telescope (LAT), the main instrument on the Gamma-ray Large Area Space Telescope (GLAST) mission under development for launch by NASA in 2006, will survey the sky in the rich yet poorly explored high-energy band between 20 MeV and 1 TeV with unprecedented resolution and sensitivity. The LAT, which benefits from the application of particle physics detection technologies to astrophysics instrumentation, has a pair-conversion silicon-strips tracker and an imaging CsI calorimeter to measure the direction and energies of gamma rays. The relatively very intense background of charged particles will be rejected primarily by an anticoincidence shield of segmented plastic scintillators. In this paper we give an overview of the many physics goals and potential reach of the LAT, describe the instrument design and performance, and report on the status of the tracker construction

[en] The current design of the Micro Strip Gas Chamber Tracker of the Compact Muon Solenoid experiment (CMS) at LHC is presented. An extensive study of the performance of the final layout MSGC detectors is being carried out in dedicated tests that reproduce LHC-like conditions. Results from these tests are reported, showing the reliability of the MSGC detectors optimized for tracking in the CMS environment

[en] MicroPattern Gas Detectors with pixel read-out are position-sensitive proportional counters obtained by coupling a gas amplifying stage to a pixel charge collection plane. Advanced PCB techniques, offering typical feature size of the order of a few microns, are used to construct the detectors, which show excellent spatial resolution and fast charge collection. In this paper it is shown how the design of the read-out system can maximize the intrinsic performance of these devices for two practical implementations, in the field of X-ray Astronomy and Plasma Imaging

[en] Polarimetry of cosmic X-rays is one of the possible observational approaches, together with spectroscopy, photometry and imaging, to study celestial sources. It can provide a general tool to explore the structure of compact sources and derive information on mass and angular momentum of supermassive objects. Comparing with the other three modalities, the development of X-ray polarimetry is modest, due to the inefficiency of traditional X-ray polarimeters. In this paper a new instrument (the Micropattern Gas Detector) to measure the linear polarization of X-ray sources with high efficiency is presented. It is based on the photoelectric effect. Angle and amount of polarization is computed from the angular distribution of the photoelectron tracks, reconstructed by a finely segmented gas detector. The device has pixel read-out allowing a full 2-D image reconstruction. The improvement in sensitivity is nearly two orders of magnitude with respect to traditional polarimeters. At the focus of a large X-ray telescope, in orbit, it can detect low level of polarization in galactic and extragalactic sources

[en] Polarimeters flown so far were based on the Thomson scattering and Bragg diffraction with intrinsically limited sensitivity. In the present paper, we review the experiments based on those techniques and discuss possible optimization and implementation for X-ray astronomy

[en] A two stage position-sensitive gas proportional counter has been constructed by tightly coupling a Gas Electron Multiplier (GEM) with a Micro-Groove Detector (MGD). The GEM was used as the first amplifying stage and was optimised to transmit close to 100% of the primary charge even at very high drift fields (10 kV/cm). Very narrow GEM-MGD separations (0-600 μm) were used so that the active volume of the detector is still very thin (3-3.6 mm) and the required drift field could be maintained using an acceptable drift voltage (around 4000 V). Very high combined gains (up to 3x10⁵) were obtained with this system. The detector was found to be spark-free in the presence of HIPs (alpha particles) up to gains in excess of 20 000

[en] Tracking properties of GEM/Micro-groove detectors have been studied at a 120 GeV muon beam at CERN. Detector efficiency reaches 98% when the signal over noise value is equal to ∼17. Spatial resolution as high as 30 μ has been measured using a Ne-DME (40-60) gas mixture

[en] We report recent results from the development and testing of two types of micropattern gas detectors - micro-strip gas chambers and GEM-based devices with two types of pixel read-out. Thirty-two micro-strip gas chambers were tested in a high intensity hadron beam as a milestone for CERN's Compact Muon Solenoid (CMS) experiment. The detectors were operated with voltage settings corresponding to 98% hit detection efficiency at CMS for a total high intensity exposure period of 493 h. All of the requirements expected by the milestone - gain stability, number of lost strips, spark rate, etc.--were met, with wide margins. In a separate investigation, we have coupled PCB pixel read-out planes to GEM foils. In one case, 2 mmx2 mm pixels were fanned out to individual discriminators and scalers to provide very fast (2 MHz/pixel) read-out; this system has been used as an imaging device to provide diagnostic information in fusion experiments. The second type of device used smaller pixels (200 μm squares) and a Flash-ADC read-out system to reconstruct individual photoelectron tracks. The angular distribution of the tracks allows the polarisation direction of polarised X-ray sources to be identified, with possible applications for future space experiments studying celestial X-ray emissions