Optical And Acoustical Studies Of The Proposed PICO-250L Dark Matter Detector

Abstract

In the first part of this work I explore the possibility of using linear alkylbenzene, the buffer liquid for the future PICO-250L detector, configured as a liquid scintillator that could provide information on the background radioactivity levels of the inner vessel. I investigate what interactions could produce scintillation light and determine their intensity and likelihood. I design different devices that help light collection and assess quantitatively their advantages and disadvantages.

In the second part of this work, I develop a 2D acoustical model of the inner vessel of the detector that reproduces the discrimination between alpha and neutron events characteristic of backgrounds in superheated liquid experiments. Such a model is crucial for understanding the propagation and reception of the acoustic signals in the chamber. Subsequently, I exploit this model to show that piezoelectric devices located in different part of the vessel yield different discrimination capability between single and multiple bubble events.