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Recent advances in detector technologies for particle therapy beam monitoring and dosimetry
No full textIn this contribution, we review the state-of-the-art of
detector technologies applied to the particle therapy (PT) field.
The increase of interest in PT has recently triggered a lot of
efforts devoted to the improvement of all the treatment technological aspects. In this review, we have focused our attention on the
recent beam delivery monitoring developments and on the study
and implementation of the novel dosimetry and microdosimetry
techniques
Measurement of ψ(2S) polarisation in pp collisions at √s = 7 TeV
No full textThe polarisation of prompt ψ(2S) mesons is measured by performing an angular analysis of ψ(2S) → μ+μ- decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb-1, collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum pT and rapidity y in the kinematic region 3.5 < pT < 15 GeV/c and 2.0 < y < 4.5, and is compared to theoretical models. No significant polarisation is observed. © 2014 CERN for the benefit of the LHCb collaboration
Measurement of Υ production in pp collisions at √s = 2.76 TeV
No full textThe production of Υ(1S), Υ(2S) and Υ(3S) mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3pb-1 collected in proton-proton collisions at a centre-of-mass energy of √s = 2.76 TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the Υ transverse momentum and rapidity, over the ranges pT < 15 GeV/c and 2.0 < y < 4.5. The total cross-sections in this kinematic region, assuming unpolarised production, are measured to be (Formula presented.) where the first uncertainty is statistical and the second systematic. © 2014 CERN for the benefit of the LHCb collaboration
LHCb: The LHCb Muon detector commissioning and first running scenarios
No full textThe LHCb Muon detector, being part of the first trigger level (L0), has been optimized in order to provide a fast and efficient identification of the muons produced in pp collisions at the LHC. The expected performances are: 95% L0 trigger efficiency within a 25ns time window and muon identification in L0 with a pT resolution of ~20%. The detector has been built, to met those stringent requirements, using Multi Wire Proportional Chambers and Gas Electron Multiplier (in the innermost region, closest to the IP) technology. The chambers (1368 MWPC + 12 GEM) are arranged in 5 detector stations, interspersed with iron filters placed along the beam pipe. While the installation of chambers in stations 2 to 5 has already been completed, the work on the first and most challenging station is still ongoing and expected to end by July 09. The results obtained in the commissioning of all the installed chambers as well as the performances measured by means of data acquired during cosmics runs since September 08 are reviewed. The strategies foreseen for the detector performance calibration, the results of the space and time alignment efforts and few first running scenarios are discussed
Detailed study of the gain of the MWPCs for the LHCb muon system
No full textThe gain of a multiwire proportional chamber (MWPC) of the LHCb muon detector was measured precisely. The chamber, filled with a CO2/Ar/CF4 gas mixture, 55/40/5% in volume, was irradiated with a 1.3 GBq Cs-137 radioactive source and the current drawn by the chamber was measured. By precisely determining the primary ionization current it was possible to evaluate the absolute gain of the chamber. The dependence of the gain on the anode voltage and the gas density was measured and the need for a gain control system during the LHCb data taking is considered. Our experimental results are compared with those predicted for the chamber gain by Diethorn formula. (c) 2007 Elsevier B.V. All rights reserved
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