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The GLUEX lead-scintillating fibre electromagnetic calorimeter

Posted on:2011-02-10Degree:Ph.DType:Thesis
University:The University of Regina (Canada)Candidate:Leverington, Blake DFull Text:PDF
GTID:2442390002950536Subject:Physics
Abstract/Summary:
The work that comprises this thesis focuses on the design and performance of the electromagnetic barrel calorimeter for the G LUEX experiment. The calorimeter is designed to measure photon four-momenta for energies from a few tens of MeV up to 4 GeV.;The Monte Carlo work was congruent with a photon beam test at Jefferson Lab where the energy and time difference resolutions, and the number of photoelectrons produced, were measured for a prototype module. The results of the beam test are presented herein.;The attenuation lengths of PHT-044 and BCF-20 scintillating fibres were extracted from measurements of the optical spectra at multiple positions along the length of the fibre. The bulk attenuation lengths were then estimated based on the quantum efficiencies of a conventional photomultiplier tube and a prototype solid-state silicon photomultiplier.;A prototype acrylic light-guide was designed to meet the requirements of transmitting light from the fibres in the barrel calorimeter to the large area silicon photomultipliers. Studies of the efficiency and transmission angles are presented.;Monte Carlo simulations were done to study the effects of the internal geometry of the lead/scintillating fibre matrix on the energy resolution and energy sampling fraction of the calorimeter.;Using the data gathered from stand-alone Monte Carlo, simulations, and measurements of readout detector properties, the results were used as parameters for a larger detector simulation, HDGEANT, which contains all the other detectors within GLUEX. Studies of the reconstruction efficiency and resolutions for single photons are presented.;To conclude the thesis work, a first attempt was made at reconstructing a physics reaction with a recoil proton and four photons from meson decays using the kinematic fitter that is part of the GLUEX reconstruction software package. A point was made to determine the hadronic background which may be included in the signal reconstruction. The process of producing the signal and background are discussed with some initial analysis of the results. As the reconstruction software is not a final version, some deficiencies were found and are discussed.
Keywords/Search Tags:Calorimeter, GLUEX, Fibre, Reconstruction
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