Particle and Astroparticle Physics Seminar

Background Reduction Techniques and Simulations for Dark Matter Search

Olivia Scallon

Laurentian University

Dark matter is one of the most challenging mysteries of cosmology. The detection of Dark Matter is a main objective in modern experimental physics. The PICO experiment (following the PICASSO experiment) work towards the direct detection of WIMPs (Weakly Interacting Massive Particles) with superheated liquid detectors. Phase transitions in the superheated liquids are triggered by the nuclear recoil caused by the elastic collision of a dark matter particle. The phase transition in the detectors leads to the formation of a gaseous bubble. The acoustic signal of the nucleation of a bubble is recorded with piezoelectric sensors and pictures of the bubbles are taken with cameras.

This presentation reviews the work done for the fabrication process and purification techniques of the PICASSO detectors which allowed a background reduction of a factor of 10. Simulations for the PICO experiment will be presented. Geant4 muon-induced neutron sim- ulations in the SNOLAB drift will be treated as well as Geant4 simulations for the design of a muon veto.