PhD thesis (working title): Study of the low-energy response of nuclear recoils in Liquid Xenon for Dark Matter applications
One of the yet unsolved mysteries of modern astroparticle physics is the nature of the so-called Dark Matter. Experiments to detect Dark Matter have been performed for several decades now, but until today it was only possible to set limits and constraints to Dark Matter particle properties. The most promising candidate for a Dark Matter particle is the WIMP (Weakly Interacting Massive Particle), which is searched for with a variety of experimental setups of which experiments with liquid xenon time projection chambers currently set the best constraints on WIMP mass and cross-section, respectively.
Dark Matter search requires detailed knowledge about the expected background and discrimination of the latter is a crucial aspect for data analysis. For the experiments of the XENON group, XENON100 and XENON1T, which consist of dual-phase xenon time projection chambers (TPC), the discrimination is carried out by measuring the ratio between light and charge for occurrent signals.
The main goal for my PhD is to examine the possible background for xenon TPC experiments, in detail the response of electronic and nuclear recoils in liquid xenon (LXe) which are caused by the scattering of gamma-rays and neutrons, respectively, off xenon atoms. The MainzTPC (currently under construction and testing) is specially designed to measure these recoil signals down to only a few keV deposited scattering energy.
The understanding of the low-energy response of nuclear recoils in LXe will improve the background discrimination for xenon TPCs.