122331374
Long-term performance of double gap resistive plate chambers under gamma irradiation
In this paper, we describe a dedicated test to study possible long-term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about and a total charge of about gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to gamma energies is measured.
15045293
The bakelite for the RPCs of the experiment CMS
Results from aging tests on the bakelite used for the CMS RPCs are presented. Samples of melaminic bakelite were exposed to a heavy gamma and neutron radiation. Data on the bulk resistivity were collected while accumulating gamma and neutron doses and particles fluence up to values well beyond those expected in 10 years of RPCs operation in the barrel region of CMS. The test with gamma radiation was performed at the CERN Gamma Irradiation Facility (GIF) with a 20 Ci 137Cs source. A total absorbed dose of 5 Gy was accumulated during an irradiation period of about one month. The test with both neutron and gamma radiation was held at the Triga Mark II 250 kW reactor located in Pavia. A total of 80 h of exposure were accumulated integrating a neutron and gamma dose of about 80 Gy and a fast neutron fluence of some . Experimental data on dose rate in both the test facilities have been compared to simulation output and show a good agreement.
56416813
Aging study for Resistive Plate Chambers of the CMS Muon Trigger Detector
A long-term aging test of a Resistive Plate Chamber (RPC) was carried out with an intense gamma source. The detector was operated in avalanche mode and had the bakelite surface treated with linseed oil. After the irradiation the estimated dose, charge and fluence were approximately equal to the expected values after 10 years of operation in the CMS barrel region. During and after the irradiation, the RPC performance was monitored with cosmic muons and showed no relevant aging effects. Moreover, no variation of the bakelite resistance was observed.
120049072
The resistive plate chambers for CMS and their simulation
In this paper some results obtained by the CMS Resistive Plate Chamber collaboration during its five years long period of research and development are reported. The importance of the simulation in the design of the Resistive Plate Chambers for CMS is stressed.
115001576
Single event effect measurements on the resistive plate chambers front-end chips for the CMS experiment
123170336
NEUTRON-INDUCED SINGLE EVENT UPSET ON THE RPC FRONT-END CHIPS FOR THE CMS EXPERIMENT
Neutrons from a reactor and from a cyclotron have been used to characterise the CMS Resistive Plate Chambers (RPCs) front-end chip to neutron-induced damaging events. Single Event Upset (SEU) cross-sections have been measured up to for different chip thresholds. Tests at a reactor were done with an integrated fast () neutron fluence of and a thermal neutron fluence of . High-energy neutrons from a cyclotron were used up to a fluence of . Data indicate the existence of a chip SEU sensitivity already at thermal energy and a saturated SEU cross-section from 3 to . Values of the SEU cross-sections from the thermal run well agree with those obtained by another CMS group that uses the same technology ( BiCMOS) though with different architecture. Cross-sections obtained with fast neutrons (from to about ) are consistently higher by one order of magnitude compared to the thermal one. The average time between consecutive SEU events in each chip of the CMS barrel RPCs can be estimated to be 1 h.
166225720
Study of J / ψ production at central rapidity with the ALICE experiment at LHC
118028873
Results on Lambda and Xi production in Pb-Pb collisions at 160 GeV/c per nucleon from the NA57 experiment
The NA57 experiment has been designed to study the onset of enhanced production of strange baryons and anti-baryons in Pb-Pb collisions with respect to p-Be collisions. This enhancement is considered a sensitive signature for a phase transition to a new state of matter -- the Quark Gluon Plasma (QGP). In this paper, we report results on Lambda and Xi hyperon production in central Pb-Pb collisions at 160 GeV/c per nucleon beam momentum.
117970185
Search for pentaquarks in WA97 experiment at CERN
The WA97 experiment at CERN has collected data aiming to study strangeness production in heavy ion collisions at 158 A GeV/c; p‐Be data were also taken as reference data. Here we show some results of an analysis of these p‐Be data in order to check for evidence of a recently claimed pentaquark state.
119419969
Transverse mass distributions of strange particles produced in Pb-Pb collisions at 158 A GeV/c
Experiment NA57 has collected high statistics, high purity samples of $K^0_s$, $\Lambda$, $\Xi$ and $\Omega$ produced in Pb-Pb collisions at 158 $A$ GeV/$c$. In this paper we present a study of the transverse mass spectra of these particles for a sample of events corresponding to about the most central 55% of the inelastic Pb-Pb cross section. We analyse the transverse mass distributions in the framework of the blast-wave model for the full sample under consideration and, for the first time at the SPS, as a function of the event centrality.
15825535
Blast-wave analysis of strange particle mT spectra in Pb–Pb collisions at the SPS
The transverse mass spectra of high statistics, high purity samples of $K^{0}_{S}, \Lambda, \Xi and \Omega$ particles produced in Pb–Pb collisions at SPS energy have been studied in the framework of the blast-wave model. The dependence of the freezeout parameters on particle species and event centrality is discussed. Results at 40 A GeV/c are presented here for the first time