2,939 research outputs found
The TOF detector of ALICE experiment: Analysis of the first cosmic data
ALICE@LHC is an experiment optimized for study of heavy-ions
collisions (Pb-Pb up to 5.5ATeV). The main aim is the search for a new state of matter (called QGP) where quarks and gluons are deconfined. Particle identification is guaranteed by a set of detectors: one of these, the
time-of-flight system plays an important role in the identification of charged hadrons (Ï€,K, p) in the momentum
range [0.5, 4] GeV/c. The first data-taking periods with cosmic rays have been a great chance to check the performance of the experimental apparatus and of the developed software for description, simulation, recostruction, visualization and analysis. A preliminary time resolution study on this cosmic rays data is presented
Response of Multi-strip Multi-gap Resistive Plate Chamber
A prototype of Multi-strip Multi-gap Resistive Plate chamber (MMRPC) with
active area 40 cm 20 cm has been developed at SINP, Kolkata. Detailed
response of the developed detector was studied with the pulsed electron beam
from ELBE at Helmholtz-Zentrum Dresden-Rossendorf. In this report the response
of SINP developed MMRPC with different controlling parameters is described in
details. The obtained time resolution () of the detector after slew
correction was 91.53 ps. Position resolution measured along ()
and across () the strip was 2.80.6 cm and 0.58 cm, respectively.
The measured absolute efficiency of the detector for minimum ionizing particle
like electron was 95.81.3 . Better timing resolution of the detector
can be achieved by restricting the events to a single strip. The response of
the detector was mainly in avalanche mode but a few percentage of streamer mode
response was also observed. A comparison of the response of these two modes
with trigger rate was studiedComment: 19 pages, 26 figure
Kaon pair production in proton-nucleus collisions at 2.83 GeV kinetic energy
The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on
C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic
spectrometer. The K- momentum dependence of the differential cross section has
been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of
the data with detailed model calculations indicates an attractive K- -nucleus
potential of about -60 MeV at normal nuclear matter density at a mean momentum
of 0.5 GeV/c. However, this approach has difficulty in reproducing the
smallness of the observed cross sections at low K- momenta.Comment: 7 pages, 5 figures, 1 tabl
Multigap RPC time resolution to 511 keV annihilation photons
The time resolution of Multigap Resistive Plate Counters (MRPCs) to keV
gamma rays has been investigated using a Na source and four detectors.
The MRPCs time resolution has been derived from the Time-of-Flight information,
measured from pairs of space correlated triggered events. A GEANT4 simulation
has been performed to analyze possible setup contributions and to support
experimental results. A time resolution (FWHM) of ps and ps has
been measured for a single MRPC with four m gas gaps by considering
respectively one and two independent pairs of detectors.Comment: 25 pages, 14 figure
Development of high-rate timing RPCs
For many applications of RPCs to time-of-flight counters in heavy ion experiments the expansion to much higher values of the counting rate capability, so far limited to around 2Â kHz/cm2 is of fundamental importance. To address this issue we developed single-gap timing RPCs with resistive electrodes made from a commercially available plastic material. Tests performed in photon beams yielded a time resolution around 90Â ps [sigma], essentially unchanged from 2Â kHz/cm2 to 27Â kHz/cm2. This result establishes the basic feasibility of timing measurements with RPCs at rates of tens of kHz/cm2, keeping a time resolution below 100Â ps [sigma] and using plastic electrode materials.http://www.sciencedirect.com/science/article/B6TJM-4CXHH16-1/1/294a04bd430f914a4663436357d765d
Subthreshold and near-threshold kaon and antikaon production in proton-nucleus reactions
The differential production cross sections of K^+ and K^- mesons have been
measured at the ITEP proton synchrotron in p+Be, p+Cu collisions under lab
angle of 10.5^0, respectively, at 1.7 and 2.25, 2.4 GeV beam energies. A
detailed comparison of these data with the results of calculations within an
appropriate folding model for incoherent primary proton-nucleon, secondary
pion-nucleon kaon and antikaon production processes and processes associated
with the creation of antikaons via the decay of intermediate phi mesons is
given. We show that the strangeness exchange process YN->NNK^- gives a small
contribution to the antikaon yield in the kinematics of the performed
experiment. We argue that in the case when antikaon production processes are
dominated by the channels with KK^- in the final state, the cross sections of
the corresponding reactions are weakly influenced by the in-medium kaon and
antikaon mean fields.Comment: 24 pages. accepted for publication at J.Phys.
Perspectives for Positron Emission Tomography with RPCs
In this study we address the feasibility and main properties of a positron
emission tomograph (PET) based on RPCs. The concept, making use of the
converter-plate principle, takes advantage of the intrinsic layered structure
of RPCs and its simple and economic construction. The extremely good time and
position resolutions of RPCs also allow the TOF-PET imaging technique to be
considered. Monte-Carlo simulations, supported by experimental data, are
presented and the main advantages and drawbacks for applications of potential
interest are discussed.Comment: Presented at "RPC2001-VI Workshop on Resistive Plate Chambers and
Related Detectors", Coimbra, Portugal, 26-27 November 2001 (5 pages
Beam tests of a large-scale TORCH time-of-flight demonstrator
The TORCH time-of-flight detector is designed to provide particle
identification in the momentum range 2-10 GeV/c over large areas. The detector
exploits prompt Cherenkov light produced by charged particles traversing a 10
mm thick quartz plate. The photons propagate via total internal reflection and
are focused onto a detector plane comprising position-sensitive Micro-Channel
Plate Photo-Multiplier Tubes (MCP-PMT) detectors. The goal is to achieve a
single-photon timing resolution of 70 ps, giving a timing precision of 15 ps
per charged particle by combining the information from around 30 detected
photons. The MCP-PMT detectors have been developed with a commercial partner
(Photek Ltd, UK), leading to the delivery of a square tube of active area 53
53mm with a granularity of 8 128 pixels equivalent. A
large-scale demonstrator of TORCH, having a quartz plate of dimensions 660
1250 10 mm and read out by a pair of MCP-PMTs with custom
readout electronics, has been verified in a test beam campaign at the CERN PS.
Preliminary results indicate that the required performance is close to being
achieved. The anticipated performance of a full-scale TORCH detector at the
LHCb experiment is presented.Comment: 12 pages, 7 figures, Paper submitted to Nuclear Instruments & Methods
in Physics Research, Section A - Special Issue VCI 201
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