DEAP (Dark Matter Experiment with Argon and Pulse Shape Discrimination) is an experiment that aims to directly detect dark matter particles via nuclear recoils in liquid argon. The experiment uses the scintillation property of liquid argon as a means to discriminate the γ and β backgrounds from the expected signal. DEAP-1 is a 7 kg single phase liquid argon detector. It was constructed to demonstrate the scalability for a larger (3600 kg) detector. The detector was originally operated at Queen’s University, where the background rejection level achieved was 6.3×10−8 for the recoil detection efficiency of 97.1%. The detector was relocated to SNOLAB, where the background in the energy region of interest was reduced by a factor of 7.7 (from 4.61±0.17 mHz to 0.60±0.05 mHz.). The background rejection level of 9.64×10−9 (10.4 part per billion) was achieved from the combined data set (Queen’s University and SNOLAB) for a recoil detection efficiency of 35.5 ± 1.3 %. With the current background rate, the background rejection level required for the 3600 kg detector (1.8×10−9 ) is projected to be achieved in 382 days at the neutron efficiency of 9.1±0.6 %. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-01-26 09:28:25.432

No description available.

No description available.

No description available.

Graduate

Graduate

No description available.

No description available.

Electrical resistivity is an important indicator of metal thin film quality. In this study, the influence of argon working pressure on the properties of metal thin films was evaluated, and the thickness effect on the resistivity of metal thin films was investigated. The sputtered thin film resistivity performances of seven metals as a function of argon pressure were measured, and the results turned out that the argon pressure was vital to film quality. Further investigation on sputtered chromium thin films using XRD, SEM and XPS revealed that the argon pressure influences the microstructure of sputtered metal thin films. Different microstructure is the reason for different resistivity performances, and John Thornton's "Zone Model" explains all these behaviours well. The resistivity of aluminum and chromium thin films with thickness from 15 to 150 nm were compared, the resistivity change significantly. The scaling trends are different for different metals. / Materials Engineering

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1963. / Bibliography: leaves 107-113. / viii, 114 l illus., diagrs., tables