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 zero degree calorimeters (ZDCs) for the ALICE experiment will measure the energy of the spectator nucleons in heavy ion collisions at the CERN LHC. The dipole magnets of the LHC beam optics will ...separate the ion beams from the spectator protons; the spectator protons and neutrons will be respectively detected by the proton (ZP) and the neutron (ZN) calorimeters. Since all the spectator nucleons have the same energy, the calorimeter response is proportional to their number, providing a direct information on the centrality of the collision. ZDCs are spaghetti calorimeters, which detect the Cherenkov light produced by the shower particles in silica optical fibers embedded in a dense absorber. The technical characteristics of ZP and ZN detectors are described. The calorimeters have been tested at the CERN SPS using pion and electron beams with momenta ranging from 50 to 200 GeV/c; the ZN detector behaviour has also been studied with an indium beam of 158 GeV/c per nucleon. The beam test results are presented: the calorimeters response, the energy resolution and the localizing capability. Also the signal uniformity and a comparison between the transverse profile of the hadronic and electromagnetic shower are discussed. Moreover the differences between the ZP detector responses to protons and pions of the same energy have been investigated, exploiting the proton contamination in the positive pion beams.
A dedicated front-end electronics has been developed for the trigger chambers of the ALICE muon spectrometer under construction at the future LHC at CERN. This trigger detector is based on RPCs ...(Resistive Plate Chambers) working in streamer mode. The number of electronics channels (about 21000) and the fact that RPC signals have specific characteristics have led to the design of an 8 channel front-end ASIC using a new discrimination technique. The principle of the ASIC is described and the radiation hardness is discussed. Special emphasis is put on production characteristics of about 4000 ASICs.
The Zero Degree Calorimeters (ZDCs) for the ALICE experiment will measure the energy of the spectator nucleons in heavy ion collisions at the CERN LHC. Since all the spectator nucleons have the same ...energy, the calorimeter reponse is proportional to their umber providing a direct information on the centrality of the collision. Two sets of ZDCs are located at opposite sides with respect to the interaction point (I), 116 m away from it Each set consists of a neutron (ZN) calorimeter, placed between the two beam pipes, an a proton (ZP) calorimeter, posioned externally to the outgoing beam pipe. The ZDCs spaghetti calorimeters, which detect the Cherenkov light produced by the shower particle in silica optical fibers embedded in a dense absorber. In summer 2007 the ZN and ZP calorimeters have been placed on a movable platform and then installed in the LHC tunnel. The results of the commissioning studies and in particular the solutions adopted to control the stability of the PMTs response will be shown: light injection with a larser diode and cosmic rays. The foreseen calibration with e.m. dissociation event in Pb-Pb collisions will also be disussed. Finally the it meaurements carried out during the commissining in the LHC tunnel will be presentend.
RPC for thermal neutron detection Arnaldi, R; Chiavassa, E; Colla, A ...
Journal of physics. Conference series,
05/2006, Letnik:
41, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The possibility to detect thermal neutrons with single gap Resistive Plate Chambers has been investigated. To detect neutrons a 10B4C thin coating on the inner surface of one RPC electrode is used as ...thermal neutron converter. The RPC detects the charged particles generated by neutrons via the (n, α) reaction on Boron. Tests on converter samples have been performed with a thermalized 252Cf source in order to evaluate the conversion efficiency: a good agreement between experimental results and simulation has been achieved. A detector prototype has been developed and tested on a low energy neutron beam at the European laboratories JRC in Belgium. A detailed description of the detector and the experimental test results are presented.
This clinical policy from the American College of Emergency Physicians addresses key issues in the evaluation and management of patients with suspected non–ST-elevation acute coronary syndromes. A ...writing subcommittee conducted a systematic review of the literature to derive evidence-based recommendations to answer the following clinical questions: (1) In adult patients without evidence of ST-elevation acute coronary syndrome, can initial risk stratification be used to predict a low rate of 30-day major adverse cardiac events? (2) In adult patients with suspected acute non–ST-elevation acute coronary syndrome, can troponin testing within 3 hours of emergency department presentation be used to predict a low rate of 30-day major adverse cardiac events? (3) In adult patients with suspected non–ST-elevation acute coronary syndrome in whom acute myocardial infarction has been excluded, does further diagnostic testing (eg, provocative, stress test, computed tomography angiography) for acute coronary syndrome prior to discharge reduce 30-day major adverse cardiac events? (4) Should adult patients with acute non–ST-elevation myocardial infarction receive immediate antiplatelet therapy in addition to aspirin to reduce 30-day major adverse cardiac events? Evidence was graded and recommendations were made based on the strength of the available data.
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