2015 CAP Congress / Congrès de l'ACP 2015

Optimizing the wavelength-shifter thickness for alpha suppression in the DEAP-3600 detector

16 Jun 2015, 16:45

15m

CCIS 1-140 (University of Alberta)

Oral (Student, In Competition) / Orale (Étudiant(e), inscrit à la compétition) Particle Physics / Physique des particules (PPD) T3-4 Cosmic Frontier: Dark Matter III (PPD)/ Frontière cosmique: matière sombre III (PPD)

Speaker

Derek Cranshaw (Queen's University)

Description

The DEAP-3600 experiment is a spherical dark matter detector searching for WIMPs by detecting scintillation light in a 3600 kg mass of liquid argon. Before the ultraviolet scintillation light passes through the optically clear acrylic vessel and light guides to the surrounding photomultiplier tubes, it must pass through a wavelength-shifting layer of tetraphenyl butadiene (TPB). Trace amounts of polonium 210 will contaminate the inner surface of the acrylic vessel as well as the TPB layer, and alpha particles resulting from its decay is expected to contribute background events to the WIMP signal. This talk will present the dependence of this background alpha signal on the thickness of the TPB layer, as well as the expected background events per 3 years of data taking at the optimized TPB thickness.

Presentation materials

Slides

CAP2015_DerekCranshawV6.pdf