ترغب بنشر مسار تعليمي؟ اضغط هنا

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

47   0   0.0 ( 0 )
 نشر من قبل Vladimir Peskov
 تاريخ النشر 2011
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

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.

قيم البحث

اقرأ أيضاً

351 - M. Blatnik 2015
Cerenkov technology is often the optimal choice for particle identification in high energy particle collision applications. Typically, the most challenging regime is at high pseudorapidity (forward) where particle identification must perform well at high high laboratory momenta. For the upcoming Electron Ion Collider (EIC), the physics goals require hadron ($pi$, K, p) identification up to $sim$~50 GeV/c. In this region Cerenkov Ring-Imaging is the most viable solution. ewline The speed of light in a radiator medium is inversely proportional to the refractive index. Hence, for PID reaching out to high momenta a small index of refraction is required. Unfortunately, the lowest indices of refraction also result in the lowest light yield ($frac{dN_gamma}{dx} propto sin^2{left(theta_C right)}$) driving up the radiator length and thereby the overall detector cost. In this paper we report on a successful test of a compact RICH detector (1 meter radiator) capable of delivering in excess of 10 photoelectrons per ring with a low index radiator gas ($CF_4$). The detector concept is a natural extension of the PHENIX HBD detector achieved by adding focusing capability at low wavelength and adequate gain for high efficiency detection of single-electron induced avalanches. Our results indicate that this technology is indeed a viable choice in the forward direction of the EIC. The setup and results are described within.
A combination Time Projection Chamber-Cherenkov prototype detector has been developed as part of the Detector R&D Program for a future Electron Ion Collider. The prototype was tested at the Fermilab test beam facility to provide a proof of principle to demonstrate that the detector is able to measure particle tracks and provide particle identification information within a common detector volume. The TPC portion consists of a 10x10x10cm3 field cage, which delivers charge from tracks to a 10x10cm2 quadruple GEM readout. Tracks are reconstructed by interpolating the hit position of clusters on an array of 2x10mm2 zigzag pads The Cherenkov component consists of a 10x10cm2 readout plane segmented into 3x3 square pads, also coupled to a quadruple GEM. As tracks pass though the drift volume of the TPC, the generated Cherenkov light is able to escape through sparsely arranged wires making up one side of the field cage, facing the CsI photocathode of the Cherenkov detector. The Cherenkov detector is thus operated in a windowless, proximity focused configuration for high efficiency. Pure CF4 is used as the working gas for both detector components, mainly due to its transparency into the deep UV, as well as its high N0. Results from the beam test, as well as results on its particle id capabilities will be discussed.
Gas Electron Multiplier (GEM) technology is being considered for the forward muon upgrade of the CMS experiment in Phase 2 of the CERN LHC. Its first implementation is planned for the GE1/1 system in the $1.5 < midetamid < 2.2$ region of the muon end cap mainly to control muon level-1 trigger rates after the second long LHC shutdown. A GE1/1 triple-GEM detector is read out by 3,072 radial strips with 455 $mu$rad pitch arranged in eight $eta$-sectors. We assembled a full-size GE1/1 prototype of 1m length at Florida Tech and tested it in 20-120 GeV hadron beams at Fermilab using Ar/CO$_{2}$ 70:30 and the RD51 scalable readout system. Four small GEM detectors with 2-D readout and an average measured azimuthal resolution of 36 $mu$rad provided precise reference tracks. Construction of this largest GEM detector built to-date is described. Strip cluster parameters, detection efficiency, and spatial resolution are studied with position and high voltage scans. The plateau detection efficiency is [97.1 $pm$ 0.2 (stat)]%. The azimuthal resolution is found to be [123.5 $pm$ 1.6 (stat)] $mu$rad when operating in the center of the efficiency plateau and using full pulse height information. The resolution can be slightly improved by $sim$ 10 $mu$rad when correcting for the bias due to discrete readout strips. The CMS upgrade design calls for readout electronics with binary hit output. When strip clusters are formed correspondingly without charge-weighting and with fixed hit thresholds, a position resolution of [136.8 $pm$ 2.5 stat] $mu$rad is measured, consistent with the expected resolution of strip-pitch/$sqrt{12}$ = 131.3 $mu$rad. Other $eta$-sectors of the detector show similar response and performance.
A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c up to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator f acility of Jefferson Laboratory. The adopted solution foresees a novel hybrid optics design based on aerogel radiator, composite mirrors and high-packed and high-segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). We report here the results of the tests of a large scale prototype of the RICH detector performed with the hadron beam of the CERN T9 experimental hall for the direct detection configuration. The tests demonstrated that the proposed design provides the required pion-to-kaon rejection factor of 1:500 in the whole momentum range.
This work illustrates and compares some methods to measure the most relevant parameters of silicon photo-multipliers (sipm{}s), such as photon detection efficiency as a function of over-voltage and wavelength, dark count rate, optical cross-talk, aft erpulse probability. For the measurement of the breakdown voltage, $V_{BD}$, several methods using the current-voltage $IV$ curve are compared, such as the IV Model, the relative logarithmic derivative, the inverse logarithmic derivative, the second logarithmic derivative, and the third derivative models. We also show how some of these characteristics can be quite well described by few parameters and allow, for example, to build a function of the wavelength and over-voltage describing the photodetection efficiency. This is fundamental to determine the working point of SiPMs in applications where external factors can affect it. These methods are applied to the large area monolithic hexagonal SiPM S10943-2832(X), developed in collaboration with Hamamatsu and adopted for a camera for a gamma-ray telescope, called the SST-1M. We describe the measurements of the performance at room temperature of this device. The methods used here can be applied to any other device and the physics background discussed here are quite general and valid for a large phase-space of the parameters.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا