Description du sujet de thèse

Improving the discovery potential of XENONnT and XLZD on detecting dark matter with the study of their electrodes

Contexte de travail

Shedding light on the nature of dark matter is one of the main priority of modern particle and astroparticle physics today.
Direct detection experiments aim to investigate particle dark matter models where this mysterious particle, travelling through our galaxy, might scatter off targets of ultra-sensitive, low-background detectors in Earth. One of the leading technologies today are the dual-phase liquid xenon Time Projection Chambers (TPC).
The size of the detectors that are currently operating is so large that new challenges need to be addressed :
1) the presence of isolated electrons or small electron clusters, challenging our capability to detect light dark matter, and
2) the difficulty of increasing the electrons extraction fraction at 100% with the current electrodes technology.
Both issues are currently under study in XENONnT, and we expect that for the next-generation XLZD detector, they would be even more problematic. With this project, we aim to tackle those two challenges, both for XENONnT and for XLZD.
From the hardware side, we are developing novel electrodes that will be tested in our small-scale TPC installed at LPNHE, named XeLab. XeLab is currently under commissioning and its TPC will be ready by January 2025.
The PhD student will be required to operate a real detector on a human scale and develop his/her expertise in the field of direct detection of dark matter.
The student will take part in data collection, data analysis and the design of several electrode prototypes, and will present the results at XLZD meetings.
He/she will also have the opportunity to join XENONnT, one of the most sensitive dark matter experiments to date, and will be in charge of data analysis with the ultimate aim of searching for light dark matter candidates, participating in the experiment's data taking and working in parallel on the design of the next-generation XLZD experiment.
The thesis work will take place in the XENON team at the Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE) in Paris. Some travel will be required to the Gran Sasso National Laboratory (LNGS) in Italy.