Due to a miscommunication during the process of transferring this manuscript from our editorial team to Production, the Members of the American College of Emergency Physicians Clinical Policies ...Committee (Oversight Committee) were not properly indexed in PubMed. This has now been corrected online.
The publisher would like to apologize for any inconvenience caused.
Due to a miscommunication during the process of transferring this manuscript from our editorial team to Production, the Members of the American College of Emergency Physicians Clinical Policies ...Committee (Oversight Committee) were not properly indexed in PubMed. This has now been corrected online.
The publisher would like to apologize for any inconvenience caused.
Due to a miscommunication during the process of transferring this manuscript from our editorial team to Production, the Members of the American College of Emergency Physicians Clinical Policies ...Committee (Oversight Committee) were not properly indexed in PubMed. This has now been corrected online.
The publisher would like to apologize for any inconvenience caused.
Due to a miscommunication during the process of transferring this manuscript from our editorial team to Production, the Members of the American College of Emergency Physicians Clinical Policies ...Committee (Oversight Committee) were not properly indexed in PubMed. This has now been corrected online.
The publisher would like to apologize for any inconvenience caused.
The use of bakelite as electrodes for resistive plate chambers is widespread. The performance of RPC's, in particular its rate capability, strongly depends on the bulk resistivity of the electrodes. ...Since the bakelite resistivity changes as a function of temperature and humidity, we have performed several resistivity measurements of a melaminic bakelite sample in order to investigate this dependence. Two sets of measurement at well controlled environmental conditions were performed: the former after relative humidity changes in the range from 80% to 20% at constant temperature, the latter varying the temperature from 15/spl deg/C to 35/spl deg/C at constant relative humidity.
The trigger detectors for the Muon Forward Spectrometer of the ALICE experiment will be single gap RPCs with low-resistivity bakelite electrodes. The detector will take data for different colliding ...systems resulting in a wide range of working conditions and requirements, especially concerning position resolution and lifetime. To this aim we have investigated the possibility to operate the RPCs both in streamer and in saturated avalanche mode with the same FE electronics. The study of the detector performance after long irradiation periods has been carried out at the Gamma Irradiation Facility at CERN with different gas mixtures: a quenched streamer gas mixture (51.5% Ar, 41.3% forane, 7.2% C/sub 2/H/sub 10/ and 1% SF/sub 6/) and a saturated avalanche mixture (88% forane, 10% C/sub 2/H/sub 10/ and 2% SF/sub 6/). We present the results of the ageing test of a final RPC in "ALICE-like" irradiation conditions using the streamer gas mixture and the results of the ageing test of a small prototype with the avalanche gas mixture.
The trigger for the ALICE muon spectrometer will be issued by single-gap, low resistivity bakelite resistive plate chambers (RPCs). The trigger system consists of four
5.5
×
6.5
m
2
RPC planes ...arranged in two stations, for a total of 72 detectors.
One hundred and sixteen detectors have been assembled and tested in Torino. The tests have been performed with the streamer mixture developed for heavy ion data-taking. The tests include: the detection of gas leaks and parasitic currents; the measurement of the efficiency with cosmic rays, with particular regard to the uniformity of the efficiency throughout the whole active surface, with a granularity of about
2
×
2
cm
2
; the measurement of the dark current and of the mean and localised noise rate.
All the RPCs produced have been characterised. Among them, the detectors to be finally installed in ALICE and some spare have been selected; 17% of all the produced detectors have been discarded.
A short description of the test set-up is given. The results of the tests are presented, with particular regard to the performance of the selected detectors.
ALICE (a large ion collider experiment) is the heavy-ion dedicated experiment at LHC. The resistive plate chamber detector (RPC) with low-resistivity bakelite electrodes was selected for the trigger ...system of the muon spectrometer. Although the main goal of ALICE is the study of nucleus-nucleus collisions, reference data in p-p interactions will be collected as well. If, on one hand, RPC operation in streamer mode is adequate for data taking with ion beams, on the other hand, the more severe ageing requirements for p-p data taking lead us to explore the possibility of operating the detector in "highly-saturated avalanche" regime. A detailed study of the signal was carried out with cosmic rays to get a more precise view of the intrinsic properties of the gas mixture (among others the streamer fraction vs. HV). The possibility of detecting avalanche signals with our FEE designed for the streamer mode was successfully investigated. Furthermore, tests with muon beam at CERN were carried out with satisfactory results in terms of efficiency, time resolution and cluster size. An analysis of the exhaust gas showed a low HF content: this is an encouraging result in view of long term stability of the detector which is at present under test.
The proton zero degree calorimeter (ZP) for the ALICE experiment will measure the energy of the spectator protons in heavy ion collisions. The ZP is a spaghetti calorimeter, which collects and ...measures the Cherenkov light produced by the shower particles in silica optical fibres embedded in a brass absorber. The details of its construction will be shown. The calorimeter has been tested at the CERN SPS in July 2004 with pion and electron beams of various momenta ranging from 50 to 200 GeV/c. The linearity of the response of the calorimeter and its energy resolution as a function of the beam energy have been measured. The preliminary results of the test are presented.
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