PICO is a direct dark matter search experiment that utilizes bubble chambers and the acoustics of
growing bubbles to discriminate signal from background events [5]. It has been shown that temperature perturbations from equilibrium significantly affect the growth of a bubble in superheated
water [17], particularly in the form of an onset delay to perceptible growth. In this thesis the temperature perturbation method is applied to superheated C3F8 to describe the acoustic background
discrimination achieved by the PICO experiment. We reproduced the delay in water and confirmed
its occurrence in C3F8. We hypothesized that the delay can be used for optical background discrimination. However, it was shown that the model does not apply to the energy deposition of different
types of particles as all of them, e.g. incoming alpha particles and neutron induced nuclear recoils,
create multiple bubbles along their tracks. Those bubbles, in the end, coalesce to form the observed
single visible bubble.
