515 research outputs found
Study of the performance of an optically r eadout triple-GEM
No full textScintillation mechanisms in gases offer the possibility of an optical readout of micropattern gas detectors. This approach takes advantage of the large progress achieved in last years in the performance of the photosensors, opening the way to the realization of high granularity and very sensitive particle trackers. In this paper, the features of a triple-GEM structure filled with a He/CF4 (60/40) mixture and readout by a CMOS sensor are described. About 130 photons are detected per primary electron produced in the sensitive gap, making it possible to achieve a space resolution of about 35 μm. The device showed to be very sensitive even to small energy deposit: 4 photons/eV of released energy were detected
ORANGE: A high sensitivity particle tracker based on optically read out GEM
No full textGEM-based detectors had a noticeable development
in last years and have successfully been employed in different
fields from High Energy Physics to imaging applications. Light
production associated to the electron multiplication allows to
perform an optical readout of these devices. The big progress
achieved in CMOS-based photo-sensors makes possible to develop
a high sensitivity, high granularity and low noise readout. In this
paper we present the results obtained by reading out the light
produced by a triple-GEM structure by means o
f a 4 mega-pixel
CMOS sensor having a noise level less than two photons per
pixel. The choice of a CF
4
rich gas mixture (He/CF
4
60/40) and a
detailed optimization of the electric fields allowed to reach a light-
yield high enough to obtain very visible signals from minimum
ionizing particles. In a test performed with 450 MeV electron
beam, about 700 photons per millimeter were collected and a
space resolution of about 75μm was obtained.
Moreover, the device showed to be very sensitive to the density
of energy deposit: a relative uncertainty of 35% was found in
the measurement of the dE/dx
Measurements of the Čerenkov light emitted by a TeO2crystal
No full textBolometers have proven to be good instruments to search for rare processes because of their excellent energy resolution and their extremely low intrinsic background. In this kind of detectors, the capability of discriminating alpha particles from electrons represents an important aspect for the background reduction. One possibility for obtaining such a discrimination is provided by the detection of the erenkov light which, at the low energies of the natural radioactivity, is only emitted by electrons. In this paper, the results of the analysis of the light emitted by a TeO2 crystal at room temperature when transversed by a cosmic ray are reported. Light is promptly emitted after the particle crossing and a clear evidence of its directionality is also found. These results represent a strong indication that erenkov light is the main, if not even the only, component of the light signal in a TeO2 crystal. They open the possibility to make large improvements in the performance of experiments based on this kind of materials. © 2012 IOP Publishing Ltd and Sissa Medialab srl
Performance of the Muon MWPC in high luminosity runs
No full textThe LHCb detector was conceived to operate with an average luminosity of 2x10cms. During the last year of the LHC run, the whole apparatus has shown to be able to perfectly acquire and manage data produced at a luminosity as high as 4x10cms. In this condition, all subdetectors operated at average particle rates higher than the design ones and in particular the detectors equipping the Muon System had to sustain a particle rate as high as 100kHz/cm. In order to study the possibility of increasing the luminosity of operation several tests were performed. This paper reports detailed studies on the performance of the LHCb Muon System in runs with a luminosity between 4 x 10cms and 10 cms
The CYGNO Experiment
No full textThe detection of ultra-rare events as the interaction of galactic dark matter (DM) candidate particles or of neutrinos originated from the Sun requires the development of innovative detection techniques. In particular future experiments for direct DM detection requires to extend their sensitivity to masses well below 10 GeV. The Cygno collaboration plans to build and operate at LNGS a cubic meter demonstrator of a gaseous time projection chamber (TPC), equipped with an optical readout and using a He:CF4 mixture kept at atmospheric pressure. The presence of low Z atoms allows to reach a competitive sensitivity to DM masses in the GeV range while the presence of fluorine can be used to set limits on a spin-dependent DM interaction cross-section. The Cygno TPC is equipped with a Gas Electron Multipliers (GEM) amplification stage of the primary ionisation electrons. Light is produced from the GEM while scientific CMOS camers and fast photodetectors are combined to obtaining a three-dimensional reconstruction of the tracks either due to nuclear or to electron recoils. The design and the sensitivity of the demonstrator based on advanced Monte Carlo simulations of the radioactivity of the materials and of the LNGS cavern are reported. Pattern recognition algorithms are used to evaluate the identification capability of nuclear recoils against electronic recoils and studied in data from small scale prototypes. Energy measurement and also sensitivity to the source directionality are also evaluated. Therefore, a Cygno TPC would also be able to detect electron recoils originated by solar neutrinos interactions. The Cygno collaboration plans to demonstrated the scalability of such detector concept to reach a target mass large enough to significantly extend our knowledge about DM nature and solar neutrinos
Study of the performance of the MWPC single gap
No full textIn this note we report the results of measurements performed with cosmic rays on single gaps of different LHCb Muon Chambers. Their main performance have been investigated in order to achieve a better comprehension of their behavior for optimizing the chamber working conditions
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