Dark Matter is one of the main puzzles in fundamental physics and Weakly Interacting Massive Particles (WIMP) are among the best-motivated dark matter particle candidates. As of today, the most sensitive experimental technique to discover the WIMPs in the mass range from 2 GeV to 10 TeV is the dual phase Time Projection Chamber (TPC) filled with noble liquids. DarkSide-20k is the next generation of Liquid Argon (LAr) TPC, which will be running at LNGS (Italy) from 2024. 

DarkSide-50, the former detector filled with 50 kg LAr, has been in operation since 2013 at LNGS and set the world's best limit for WIMPs with masses in the few GeV/c2 range. For higher mass WIMPs, DarkSide-50 has demonstrated the LAr extraordinary and unique potential in searching for WIMPs in a zero-background regime. These features will allow an unprecedented research with DarkSide-20k that will be filled with 50 tons of LAr, so an active mass 1000 times greater than that of DarkSide-50. In addition, DarkSide-20k will benefit from an improved detector design and especially from the use of new generation photosensors, Silicon Photomultipliers (SiPM), customly developed by the DarkSide Collaboration with FBK, with low dark count rate and high radiopurity. Beyond the search for dark matter, DarkSide-20k also has strong potential in neutrino physics, particularly for neutrinos from the Sun and Supernovae.  

Within the DarkSide program, APC is leading data reconstruction, simulation, and data analysis. The new python-based data reconstruction framework, based on fast signal processing with the so-called matched filter, has been tested in ReD, a small-scale LAr TPC, and will be used for data from the “prototype”. This is a 1-ton LAr TPC, under construction at CERN, that will be operational from 2022.  

The PhD candidate will participate in the on-site commissioning, calibration and data taking of the 1-ton prototype. In addition, he/she will  contribute to the data reconstruction and analysis. Key detector parameters derived from the prototype response study, such as scintillation and ionization yields and time profiles, will be used by the candidate to investigate the DarkSide-20k detector response through Geant4 Monte Carlo simulations. The overall impact on the DarkSide-20k sensitivity to dark matter particle interactions and, possibly, on neutrino physics will be also evaluated. Some experience in C++ and/or Python programming and particle physics data analysis would be appreciated.