Author : 曾熙旻
Publisher : Open Dissertation Press
ISBN 13 : 9781374667082
Total Pages : pages
Book Rating : 4.6/5 (67 download)
Book Synopsis Simulations and Software Developments for Cosmic-Ray and Particle Physics Experiments in Underground Laboratories by : 曾熙旻
Download or read book Simulations and Software Developments for Cosmic-Ray and Particle Physics Experiments in Underground Laboratories written by 曾熙旻 and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Simulations and Software Developments for Cosmic-ray and Particle Physics Experiments in Underground Laboratories" by 曾熙旻, Hei-man, Tsang, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled SIMULATIONS AND SOFTWARE DEVELOPMENTS FOR COSMIC-RAY AND PARTICLE PHYSICS EXPERIMENTS IN UNDERGROUND LABORATORIES submitted by Tsang Hei Man for the Degree of Master of Philosophy at The University of Hong Kong in October 2007 The aim of the Daya Bay Reactor Neutrino Experiment is to measure θ, the last 13 unknown mixing angle that characterizes the neutrino oscillation phenomenon, to a sensitivity level of 0.01 or better in sin θ with a confidence level of 90%. To 13 achieve such an accuracy, background suppression is essential. While the Daya Bay Experiment will be performed underground to shield against low energy cosmic-ray muons, the measurement can also be affected by, for example, spallation neutronsby cosmic-ray muons and natural radioactivity in the surrounding environment. TheAberdeenTunnelExperimentinHongKongaimstomeasurebackgroundra- diationinasimilarundergroundenvironment. Inparticular, thespallationneutrons induced by cosmic-ray muons will be measured using a muon tracker and a neutron detector. In addition to muon-induced background, gamma radiations from natural 238 232 radioactivesources, forexampletheradio-nuclidesinthe U seriesand Thseries 40 and K, can also, potentially, create chance coincidence in the detectors, which is similar to a muon-induced signal expected in the Daya Bay Experiment. Inthisstudy, theperformanceofGEANT4, asimulationtoolforparticlephysics experiments, in gamma simulations was first validated by comparison with experi- mentalmeasurementandothersimulationmethods, includingafiniteelementsimu- lation. Then, someGEANT4simulationstudiesonthenecessityofleadshieldingfor reducing low energy gamma background from rock in the Aberdeen Tunnel Experi- ment was performed. The use of lead shielding in the Aberdeen Tunnel Experiment can be avoided by choosing suitable time windows for the detectors. The effect of background gamma radiation from radio-nuclides in the rock on Resistive Plates Chambers (RPC) in the Daya Bay Experiment was also assessed by means of a GEANT4 simulation of the RPC setup in the Daya Bay Experiment. The results were consistent with previous experimental measurements and suggest that the chance coincidence of RPCs by gamma can be reduced significantly by the use of spacers and requiring multiple coincidence.ThedataacquisitionsoftwaredevelopmentfortheAberdeenTunnelExperiment was described. Finally, a discussion on the offline analysis program for the recon- struction of muon tracks and muon angular distribution written for the Aberdeen Tunnel Experiment was presented. A simple test for verifying the offline analysis program was also performed. DOI: 10.5353/th_b3955703 Subjects: Particles (Nuclear physics) Cosmic rays Gamma rays
