Publications (17)1.21 Total impact
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Article: Identification of High $\rm p_{\perp}$ Particles with the STAR-RICH Detector
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ABSTRACT: The STAR-RICH detector extends the particle identification capapbilities of the STAR experiment for charged hadrons at mid-rapidity. This detector represents the first use of a proximity-focusing CsI-based RICH detector in a collider experiment. It provides identification of pions and kaons up to 3 GeV/c and protons up to 5 GeV/c. The characteristics and performance of the device in the inaugural RHIC run are described.12/2002; -
Article: A system of 4400 silicon microstrips readout with analog multiplexed electronics used in the WA75 experiment
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Article: Drift chambers with controlled charge collection geometry for the NA34/HELIOS experiment
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Article: Fast RICH detector using a MWPC at atmospheric pressure with a pad structure read out by VLSI circuits
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Article: Development of a fast RICH detector using a MWPC at low gain with pad readout and a NaF radiator
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Article: Review of the development of cesium iodide photocathodes for application to large RICH detectors
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ABSTRACT: CsI photocathodes were studied in order to evaluate their potential use as large photoconverters in RICH detectors for the PID system at ALICE (LHC in heavy ion collider mode). It has been demonstrated that a quantum efficiency comparable to the reference value obtained on small samples can be obtained on CsI layers evaporated on large pad electrodes operated in a MWPC at atmospheric pressure. We present a survey of the results obtained in the laboratory on small samples irradiated with UV-monochromatic beams and with RICH detectors of proximity-focusing geometry at a 3 GeV/c pion beam. -
Article: The Present Development of CsI Rich Detectors for the ALICE Experiment at CERN
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ABSTRACT: The ALICE Collaboration plans to implement a 12m^2 array consisting of 7 proximity focussed C6F^14 liquid radiator RICH modules devoted to the particle identification in the momentum range: 1 GeV/c - 3.5 GeV/c for pions and kaons. A large area CSI-RICH prototype has been designed and built with the aim to validate the detector parameter assumptions made to predict the performance of the High Momentum Particle Identification System (HMPID) of the ALICE Experiment. The main elements of the prototype will be described with emphasis on the engineering solutions adopted. First results from the analysis of multitrack events recorded with this prototype exposed to hadron beams at the CERN SPS will be discussed List of Figures Figure 1 General view of the ALICE lay-out Figure 2 Schematic layout of the fast CsI-RICH Figure 3 Perspective view of the HMPID layout with the seven RICH modules tilted according to their position with respect to the interaction vertex. The frame that supports the detectors is also shown Figure 4 Top view of the photodetector anode plane with the wire support spacer. One CsI board, out of six forming the pad cathode plane, is also shown. Figure 5 Perspective view of the HMPID honeycomb panel with the three radiator vessels Figure 6 Cut away view of the HMPID CsI-RICH showing separately each detector component. Kapton buses that carry signals from the pads to the readout electronics are also shown Figure 7 a)number of resolved photoelectrons per event, b)reconstructed Cherenkov angle per photon Figure 8 C6F14 transmission plots before and after the molecular sieve purification Figure 9 Display plot showing an SPS event. Three tracks are reconstructed by using the tracking chamber telescope, the associated rings are shown in the HMPID prototype This publication also appears as INT-98-20 . -
Article: A large area CsI RICH Detector in ALICE at LHC
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ABSTRACT: A 1m<SUP>2</SUP> CsI RICH prototype has been successfully tested in a hadron beam at CERN SPS. The prototype, fully equipped with 15k electronic channels, has been used to identify particles coming from pi-Be interactions. Track reconstruction has been performed by using a telescope consisting of four gas pad chambers. A detailed description of the detector will be presented and results from the test will be discussed. List of figures Figure 1 Expected proton and antiproton yields including jet quenching mechanism in central Pb-Pb collisions at LHC. Figure 2 Schematic view of the HMPID CsI-RICH Figure 3 Experimental layout used at the SPS/H4 test beam Figure 4 Distributions of the mean number, per ring, of pad hits ( N<SUB>pad</SUB> ), electrons ( N<SUB>tot</SUB> ) and Cherenkov photoelectrons ( N<SUB>res</SUB> ) as a function of the single-electron mean pulse height Figure 5 Mean single-electron pulse height as a function of high voltage measured at the centre of each of the four photocathodes Figure 6 Evaluation of the uniformity of the chamber gain for the photocathode PC32 Figure 7 Azimuthal distribution of the photon pad hits in the Cherenkov fiducial zone (HV=2050 V) Figure 8 Photon angle (a) and track Cherenkov angle (b) distributions for beam events at the SPS Figure 9 Track density on the HMPID cathode plane in real 350 GeV/c pi<SUP>-</SUP>-Be events Figure 10 Three dimensional display of an SPS 350 GeV/c pi<SUP>-</SUP>-Be event. Eleven tracks are reconstructed in the telescope by requiring one hit on each pad chamber to reconstruct a track -
Article: Study of the Quantum Efficiency of CsI Photocathodes Exposed to Oxygen and Water Vapour
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ABSTRACT: The operation of CsI photocathodes in gaseous detectors requires special attention to the purity of the applied gas mixtures.We have studied the influence of oxygen and water vapour contaminations on the performance of CsI photocathodes for theALICE HMPID RICH prototype. Measurements were done through comparison of Cherenkov rings obtained from beamtests. Increased levels of oxygen and water vapour did not show any effect on the performance. The results of this studyfound a direct application in the way of storing CsI photocathodes over long periods nad in particular in the shipment of theHMPID prototype from CERN to the STAR experiment at BNL. (Abstract only available,full text to follow) -
Article: The STAR-RICH Detector
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ABSTRACT: The STAR-RICH detector extends the particle idenfication capabilities of the STAR spectrometer for charged hadrons at mid-rapidity. It allows identification of pions and kaons up to ~3 GeV/c and protons up to ~5 GeV/c. The characteristics and performance of the device in the inaugural RHIC run are described. -
Article: A progress report on the development of the CsI-RICH detector for the ALICE experiment at LHC
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ABSTRACT: The particle identification in ALICE (A Large Ion Collider Experiment) at LHC will be achieved by two complementary systems based on time of flight measurement, at low $p_t$, and on the Ring Imaging Cherenkov (RICH) technique, at $p_t$ ranging from 2 to 5 GeV/$c$, respectively. The High Momentum PID (HMPID) system will cover $\sim$5\% of the phase space, the single arm detector array beeing composed by seven 1.3$\times$1.3 m$^2$ CsI-RICH modules placed at 4.7 m from the interaction point where a density of about 50 particles/m$^2$ is expected.\\ A 1 m$^2$ prototype, 2/3 of HMPID module size, has been successfully tested at the CERN/PS beam where 18 photoelectrons per event have been obtained with 3 GeV/c pions and 10 mm liquid $\mathrm{C}_6\mathrm{F}_{14}$ radiator. Mechanical problems related to the liquid radiator vessel construction have been solved and the prototype, fully equipped, will be tested at the CERN/SPS to investigate the PID capability in high particle density events.\\ In this report, after an introductory discussion on the requirements for PID in ALICE, the HMPID prototype is described and the main results of beam tests on large area CsI photocathodes, operated in RICH detectors, are given. -
Article: A threshold imaging Cerenkov detector with CsI photocathodes
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ABSTRACT: A Threshold Imaging Cherenkov (TIC) detector, in conjunction with a tracking device and a time-of-flight system, has been developed to allow pion, kaon and proton identification in the 3--8 GeV/$c$ range of momenta. The system allows spatial identification of the photons of particles above the Cherenkov threshold and their correlation to a particular track. The TIC detector uses a MWPC detector with a CsI coated photocathode for photon conversion. The results obtained in ultrarelativistic lead--lead collisions at the CERN SPS accelerator are presented. -
Article: Final tests of the CsI-based ring imaging detector for the ALICE experiment
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ABSTRACT: We report on the final tests performed on a CsI-based RICH detector equipped with 2 C$_6$F$_{14}$ radiator trays and 4 photocathodes, each of 64$\times$38 cm$^2$ area. The overall performance of the detector is described, using different gas mixtures, in view of optimizing the photoelectron yield and the pad occupancy. Test results under magnetic field up to 0.9 T, photocathode homogeneity and stability are presented. -
Article: Performance of large area CsI-RICH prototypes for ALICE at LHC
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ABSTRACT: We present the performances of large area CsI-RICH prototypes obtained in single particle events. The differential quantum efficiency of the photocathodes has been deduced from Cherenkov rings by means of two different procedures: a direct measurement with a thin NaF radiator and a Monte Carlo based estimation for a C$_6$F$_{14}$ radiator. A factor of merit of 45 cm$^{-1}$ has been found for the typical detector configuration. Two angle reconstruction algorithms have been used and the different errors affecting the Cherenkov angle resolution have been estimated combining the analytical treatment and the Monte Carlo simulation. Also the dependence on radiator thickness, Cherenkov ring radius, chamber voltage and particle incidence angle has been studied. -
Article: The CsI-based Ring Imaging Detector for the ALICE experiment: technical description of a large prototype
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ABSTRACT: We report on the design and construction of a CsI-RICH detector composed of four CsI photocathodes, of 64$\times$40 cm$^2$ each, and two C$_6$F$_{14}$ radiator trays, of 133$\times$41 cm$^2$. A detailed description of the novel elements is given and the performance of the detector is illustrated with some basic results obtained during the tests at the beam. -
Article: Fast RICH detector with a caesium iodide photocathode at atmospheric pressure
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Article: Cleaning and recirculation of perfluorohexane (C6F14) in the STAR-RICH detector
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ABSTRACT: A RICH detector with a CsI photo-cathode and liquid perfluorohexane radiator has been installed in the STAR experiment at RHIC. The liquid is continuously cleaned and distributed to a quartz containment vessel within the detector by a closed recirculation system. A VUV spectrometer is connected to the system which monitors the optical transparency of the liquid. This measurement provides one of the pieces of information necessary to model the number of Cherenkov photons which reach the pad plane. A description of the liquid recirculation system and the cleaning procedure for the liquid as well as the spectrometer is presented along with results of their performance.Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 486(3):590-609. · 1.21 Impact Factor
