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, Volume:
602, Issue:
3
Journal Article
Peer reviewed
Open access
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 MRPC (multi resistive plate chamber) strip is the basic element of the ALICE time-of-flight detector. A test of a large sample of MRPC-strip prototypes corresponding to 1.2% of the full detector ...was carried out during the autumn of 2002 at the CERN proton syncroton facility. This paper summarizes the main results obtained in terms of uniformity of response for all the tested channels.
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 \(\sqrt{s_{{\text{NN}}} = 5.5\,\text{TeV}\).
We present in this paper a study of the Alice-TOF Multigap Resistive Plate Chamber (MRPC) performance by using several gas mixtures. We also present a search for possible ageing effects, by studying ...two MRPCs irradiated at the CERN Gamma Irradiation Facility.
A study of the multigap RPC at the gamma irradiation facility at CERN Akindinov, A.; Alici, A.; Anselmo, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2002, Volume:
490, Issue:
1
Journal Article
Peer reviewed
The selected device for the ALICE Time-of-Flight array is the Multigap Resistive Plate Chamber (MRPC). We have tested this device at the Gamma Irradiation Facility at CERN to evaluate the rate ...dependence. We find that the rate capability of the MRPC easily exceeds the
50
Hz/cm
2
maximum expected rate at the ALICE experiment. In addition, we have measured the power dissipated for an equivalent flux of
1.6
kHz/cm
2
of through-going muons to be
650
mW/m
2
.
Scintillation tiles with MRS APD light readout (START) are proposed to be used as basic triggering units of a cosmic muon facility intended for regular tests of all of the numerous ALICE TOF modules ...in the course of their mass production and exploitation. A prototype 32-channel array of STARTs has been assembled and tested with cosmic rays and beam. With the bias voltage at approximately 50
V, the system has shown operational consistency and homogeneity, almost 100% detection efficiency over the whole surface and intrinsic noise of
10
-
2
Hz
per detecting unit. If STARTs are to be mass-produced, the cost of a mosaic array is estimated at a moderate level of 3–
4
kUSD
/
m
2
.
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.
AbstractA procedure developed to achieve particle identification in very high multiplicity conditions using a complex time-of-flight system is illustrated in detail by simulating and studying the ...performance of the ALICE TOF detector in a realistic scenario of Pb-Pb and p-p interactions at LHC.
Construction and tests of the MRPC detectors for TOF in ALICE Akindinov, A.; Alici, A.; Antonioli, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2009, Volume:
602, Issue:
3
Journal Article
Peer reviewed
CERN-LHC (Large Hadron Collider) accelerator facility will provide heavy ions (Pb–Pb) collisions with a center-of-mass (CM) energy of about 5.5
TeV per nucleon pair. In the extreme conditions of ...temperature and energy density created in such collisions, a transition from hadronic matter towards a deconfined state of quarks and gluons is predicted by Quantum Chromodynamics (QCD) calculations on the lattice. The Time Of Flight (TOF) detector system of the ALICE (A Large Ion Collider Experiment) apparatus, is presently progressing in the assembling process at LHC at CERN. The TOF, in combination with the other central tracking detectors of ALICE provides an excellent Particle IDentification (PID) in the momentum range
0.2
–
2.5
GeV
/
c
for
K
/
π
and up to 4
GeV/
c for K/p. The ALICE TOF is a barrel detector consisting of double-stack Multigap Resistive Plate Chamber (MRPC) strips, equipped with readout pads. The MRPC is characterized by an intrinsic time resolution below 50 ps and an efficiency over 99%. The assembling procedures, the tests of mechanics, cooling system and electronics of the 8
m long TOF “supermodules”, together with the performance tests before installation in the experimental area, will be presented.
All the steps which led to the construction of the ALICE-TOF detector were strictly followed by a set of quality assurance procedures to guarantee high and uniform performances. Once a module of the ...detector (whose basic element is the Multigap Resistive Plate Chamber) is assembled, a final test concerning the data readout applies. While the detector is taking data, both during test and physics runs, a check of the quality of the data is needed. For this purpose some monitoring tools have been developed. These tools have been used since the beginning of the TOF commissioning and finally they have also been successfully used during the first global data-taking test-runs of ALICE.
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