Speaker
Description
Detectors filled with noble liquids represent an outstanding technology for the direct dark matter search, both in terms of the radiopurity and the high sensitivity to low energy signals, due to the high scintillation yield. For instance, this allowed the set of the most stringent exclusion limits for WIMPs below 10 GeV/c^{2} with only 50 kg of liquid argon, as done by DarkSide-50 collaboration in 2018. In the next years, the relative cheapness of the argon will allow for a straightforward scaling at high masses, up to 50 tons with DarkSide-20k. In these future detectors, the vacuum technology will be exchanged for the solid-state one; in DarkSide-20k the photodetection will be performed by ~ 80 thousand silicon photomultipliers (SiPMs).
All the R&D employed for the next DarkSide detectors has also converged in medical physics, specifically into the 3DPi project. The project aims to realize the first Time-Of-Flight Positron Emission Tomography (TOF-PET) scanner in liquid argon. The scanner will consist of a cylindrical cryostat fully surrounding the patient, filled with liquid Argon doped with Xenon, in order to suppress the liquid argon triplet state and guarantee a scintillation time of O(10) ns. The scintillation light will be observed by Silicon Photomultipliers, custom-designed by Fondazione Bruno Kessler, who has also developed the photosensor for DarkSide future detectors. The high availability of the argon will allow the build of total body scanners, usually prohibitive in commercial TOF-PET scanners due to the high cost of crystals. In fact, according to the Monte Carlo simulations, the 3DPi scanner will present a 200-fold increase in sensitivity, spatial resolutions comparable to commercial PET scanners and reduce the scanning time from 30 minutes down to less than one minute. Moreover, the Cherenkov light from ionized electrons might further improve the spatial resolution, with the eventual possibility to perform low dose scannings, fundamental for children and pregnant. The 3DPi is the main outcome in the daily life of the DarkSide dark matter search, as it will make the PET scanning available to a much wider range of patients and hospitals.
| First author | Michela Lai |
|---|---|
| michela.lai@ca.infn.it | |
| Collaboration / Activity | 3DPi |
