The application of Micromegas for sampling calorimetry puts specific constraints on the design and performance of this gaseous detector. In particular, uniform and linear response, low noise and ...stability against high ionisation density deposits are prerequisites for achieving good energy resolution. A Micromegas-based hadronic calorimeter was proposed for an application at a future linear collider experiment and three technologically advanced prototypes of 1×1m2 were constructed. Their merits relative to the above-mentioned criteria are discussed on the basis of measurements performed at the CERN SPS test-beam facility.
In July 2012, the ATLAS and CMS collaborations at the CERN Large Hadron Collider announced the observation of a Higgs boson at a mass of around 125 gigaelectronvolts. Ten years later, and with the ...data corresponding to the production of a 30-times larger number of Higgs bosons, we have learnt much more about the properties of the Higgs boson. The CMS experiment has observed the Higgs boson in numerous fermionic and bosonic decay channels, established its spin-parity quantum numbers, determined its mass and measured its production cross-sections in various modes. Here the CMS Collaboration reports the most up-to-date combination of results on the properties of the Higgs boson, including the most stringent limit on the cross-section for the production of a pair of Higgs bosons, on the basis of data from proton-proton collisions at a centre-of-mass energy of 13 teraelectronvolts. Within the uncertainties, all these observations are compatible with the predictions of the standard model of elementary particle physics. Much evidence points to the fact that the standard model is a low-energy approximation of a more comprehensive theory. Several of the standard model issues originate in the sector of Higgs boson physics. An order of magnitude larger number of Higgs bosons, expected to be examined over the next 15 years, will help deepen our understanding of this crucial sector.
Sampling calorimeters can be finely segmented and used to detect showers with high spatial resolution. This imaging power can be exploited at future linear collider experiments where the measurement ...of jet energy by a Particle flow method requires optimal use of tracking and calorimeter information. Gaseous detectors can achieve high granularity and a hadron sampling calorimeter using Micromegas chambers as active elements is considered in this paper. Compared to traditional detectors using wires or resistive plates, Micromegas is free of space charge effects and could therefore show superior calorimetric performance. To test this concept, a prototype of 1×1m2 equipped with 9216 readout pads of 1×1cm2 has been built. Its technical and basic operational characteristics are reported.
MICRO MEsh GAseous Structure (MICROMEGAS) and Gas Electron Multipliers (GEM) detectors are two candidates for the active medium of a Digital Hadronic CALorimeter (DHCAL) as part of a high energy ...physics experiment at a future linear collider (ILC/CLIC). Physics requirements lead to a highly granular hadronic calorimeter with up to thirty million channels with probably only hit information (digital readout calorimeter). To validate the concept of digital hadronic calorimetry with such small cell size, the construction and test of a cubic meter technological prototype, made of 40 planes of one square meter each, is necessary. This technological prototype would contain about 400 000 electronic channels, thus requiring the development of front-end ASIC. Based on the experience gained with previous ASIC that were mounted on detectors and tested in particle beams, a new ASIC called MICROROC has been developped. This paper summarizes the caracterisation campaign that was conducted on this new chip as well as its integration into a large area Micromegas chamber of one square meter.
The recent progress in R&D of the Micromegas detectors for hadronic calorimetry including new engineering-technical solutions, electronics development, and accompanying simulation studies with ...emphasis on the comparison of the physics performance of the analog and digital readout is described. The developed prototypes are with 2 bit digital readout to exploit the Micromegas proportional mode and thus improve the calorimeter linearity. In addition, measurements of detection efficiency, hit multiplicity, and energy shower profiles obtained during the exposure of small size prototypes to radioactive source quanta, cosmic particles and accelerator beams are reported. Eventually, the status of a large scale chamber (1 × 1 m2) are also presented with prospective towards the construction of a 1 m3 digital calorimeter consisting of 40 such chambers.
Prototypes of MICROMEGAS chambers, using bulk technology and analog readout, with 1x1cm2 readout segmentation have been built and tested. Measurements in Ar/iC4H10 (95/5) and Ar/CO2 (80/20) are ...reported. The dependency of the prototypes gas gain versus pressure, gas temperature and amplification gap thickness variations has been measured with an 55Fe source and a method for temperature and pressure correction of data is presented. A stack of four chambers has been tested in 200GeV/c and 7GeV/c muon and pion beams respectively. Measurements of response uniformity, detection efficiency and hit multiplicity are reported. A bulk MICROMEGAS prototype with embedded digital readout electronics has been assembled and tested. The chamber layout and first results are presented.
The AMS-02 lead-scintillating fibres Electromagnetic Calorimeter Adloff, C.; Basara, L.; Bigongiari, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2013, Letnik:
714
Journal Article
Recenzirano
The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a fine grained lead-scintillating fibres sampling calorimeter that allows for a precise three-dimensional imaging of the ...longitudinal and lateral shower development. It provides a high (≥106) electron/hadron discrimination with the other AMS-02 detectors 1 and good energy resolution. The calorimeter also provides a standalone photon trigger capability to AMS-02. The mechanical assembly was realized to ensure minimum weight, still supporting the intrinsically heavy calorimeter during launch. ECAL light collection system and electronics are designed to measure electromagnetic particles over a wide energy range, from GeV up to TeV. A full-scale flight-like model was tested using electrons and proton beams with energies ranging from 6 to 250GeV.
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