The Time-Of-Flight (TOF) detector of the ALICE experiment at the CERN LHC is based on Multi-gap Resistive Plate Chambers (MRPCs) technology. During the 2009-2013 data taking the TOF system had very ...stable operations with a total time resolution of 80ps. Details of the different calibration procedures and performance with data from collisions at the LHC will be described.
Various experiments are searching for detectors that can cover large areas (as in the present LHC experiments) with excellent timing performances and insensitivity to magnetic field. A detector based ...on scintillators coupled to SiPM can fulfil these requirements. SiPMs are indeed replacing the standard PhotoMultiplier technology thanks to the many advantages, with the corresponding possibility to achieve also higher segmentations in calorimetry or other applications. Also in view of future colliders experiments like HL-LHC or FCC or medical applications like TOF-PET, an important R&D on timing performances of SiPMs-scintillator detectors has begun, with the goal of including them in the list of possible 4-D tracking-timing devices.
An R&D on SiPM coupled to scintillator time resolution has been performed in a cosmic ray setup. Different kind of SiPMs, geometries of SiPMs coupled to the scintillator and different size of scintillator have been also studied. A time resolution of ∼69 ps, comprehensive of the full electronic chain, from the front-end to the readout electronics, has been achieved with SiPMs coupled to a 2x2x3 cm3 plastic scintillator.
This paper reports on the results of time resolution measurements of detectors consisting of SiPMs coupled to a scintillator. The R&D has been performed both in a cosmic-ray setup, at the Bologna ...INFN laboratories, and in a beam test, at the CERN T10 beam line. Different couplings, direct or by means of optical fibres, have been tested. The measurements indicate that to reach better time resolutions, it is important to have a direct coupling between the SiPM and the scintillator. A time resolution of 67 ps has been achieved, for the direct coupling, broadened by the full electronics chain jitter.
The Time-Of-Flight (TOF) detector of the ALICE experiment at the CERN LHC is based on Multi-gap Resistive Plate Chambers (MRPCs) capable to achieve a time resolution better than 50
ps. The TOF ...detector consists of about 153
000 readout channels covering a total area of about
150
m
2
. In this paper the results of the commissioning of the full TOF are reported, including the first calibration results obtained with cosmic rays.
The Time-Of-Flight detector (TOF) of the ALICE experiment at the CERN LHC is based on Multi-gap Resistive Plate Chambers (MRPCs). The TOF detector consists of 152928 readout channels covering a total ...area of 141 m
2
. In this paper the results of the calibration with cosmic-ray data collected during 2009 are presented.
Final test of the MRPC production for the ALICE TOF detector Akindinov, A.; Alici, A.; Antonioli, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2009, Letnik:
602, Številka:
3
Journal Article
Recenzirano
Odprti dostop
During the autumn of 2006 a final test of a sample of double-stack MRPC (Multigap Resistive Plate Chamber) strips, randomly chosen from two years of mass production (the ALICE Time-Of-Flight detector ...is made of 1638 strips), was carried out at the CERN Proton Synchrotron facility. The results on the performances of the MRPCs and of the front-end and readout electronics will be presented. It is confirmed that these devices have a very good uniformity of response, a long streamer-free plateau, an efficiency higher than 99% and an “intrinsic” time resolution better than about 40
ps.
The goal of the ALICE Time-of-Flight detector, based on MRPC technology, is to perform the charged-particle identification at midrapidity, in the region |
η|<0.9. This large area (∼150
m
2), finely ...segmented detector (∼157,000 channels), provides fast signals which will contribute to the Level 0 and Level 1 trigger decisions. We use the TOF detector information to perform an online estimate of the total track multiplicity and to identify simple and peculiar topologies, like those produced by minimum bias p–p, Ultra Peripheral ion–ion collisions and cosmic muons. The system architecture foresees a first layer of 72 VME boards interfacing the detector front-end to a second layer, which receives and processes all the information and takes trigger decisions.
The ALICE Time-Of-Flight (TOF) detector is a cylindrical array with a total area of about 150
m
2 and more than 153,000 readout channels; it will allow charged hadron separation for momentum up to a ...few GeV/
c. The very good performance required for such a system has been achieved by means of the Multigap Resistive Plate Chamber (MRPC) whose time resolution is better than 50
ps with an overall efficiency close to 100%. The TOF detector is fully installed since April 2008; it has successfully been operated during cosmic ray data taking. The very good stability, noise level and time performance are reported here. The status of the calibration and the first physics results with the TOF detector are given.
In this work we explore the possibility to perform “effective energy” studies in very high energy collisions at the CERN large hadron collider (LHC). In particular, we focus on the possibility to ...measure in pp collisions the average charged multiplicity as a function of the effective energy with the ALICE experiment, using its capability to measure the energy of the leading baryons with the zero degree calorimeters. Analyses of this kind have been done at lower centre-of-mass energies and have shown that, once the appropriate kinematic variables are chosen, particle production is characterized by universal properties: no matter the nature of the interacting particles, the final states have identical features. Assuming that this universality picture can be extended to ion–ion collisions, as suggested by recent results from RHIC experiments, a novel approach based on the scaling hypothesis for limiting fragmentation has been used to derive the expected charged event multiplicity in AA interactions at LHC. This leads to scenarios where the multiplicity is significantly lower compared to most of the predictions from the models currently used to describe high energy AA collisions. A mean charged multiplicity of about 1000–2000 per rapidity unit (at η∼0) is expected for the most central Pb–Pb collisions at \(\sqrt{s_{{\text{NN}}} = 5.5\,\text{TeV}\).
Pre-installation tests and calibration of the ALICE TOF modules Akindinov, A.; Alici, A.; Antonioli, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2012, 2012-1-00, Letnik:
661
Journal Article
Recenzirano
Before installation into the ALICE experiment, all 87 modules of the TOF system had to undergo a series of tests. Initial check-ups included control of the gas tightness, readout connections quality, ...and high-voltage tests. Further tests were performed on a specially constructed Cosmic Ray Test Facility, where main characteristics of the modules were scanned under the working high voltage by means of cosmic muons. All TOF channels proved to provide the detection efficiency of more than 97% and time resolution of 80–110
ps, which complies with the ALICE requirements.
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