Fiducializing the DRIFT 2 Dark Matter Detector: Data Fitting and Pulse Processing

Abstract

It is believed that about 90 to 99% of the mass of the universe is composed of a non-baryonic, non-luminous substance called dark matter. It is still unknown what exactly dark matter is, but one possible candidate is a population of Weakly Interactive Massive Particles (WIMP). DRIFT2a (Directional Recoil Identification From Tracks) is a dark matter detector designed to search for WIMPS. The analysis for DRIFT2a involves looking at electric pulses (events) that correspond to ionization inside the detector due to interactions with WIMPs and other particles. One significant problem with those pulses is that due to hardware errors they are asymmetric and have an overshoot. The main purpose of this particular project is to find a way to get rid of the overshoot through software simulations and manipulations and restore the original correct pulse. This is necessary because once the original symmetric pulses are obtained the ionization due to diffusion inside the detector could be measured. Knowing the effect of diffusion on an electric signal, one can calculate the distance the event occurred from the MWPC (Multi-wire Proportional Chamber ? the ?processor? of the detector). The process of figuring out where the event actually occurred is called Fiducializing the detector and is very important for the data analysis further on.