The LiquidO PET project (or LPET) was first proposed by the CNRS’ IJCLab team (A. Cabrera), arising from the LiquidO specialisation on e+ (or β+) detection tagged by its annihilation. This is a common feature in MeV anti-neutrino detection, for example, those emitted from nuclear reactors and the radioactivity of the planet Earth (or geoneutrinos).
LPET relies on some of the same main principles of neutrino detection in a low-density and low z material(s), such as the liquid scintillator as a basis, so that the full Compton pattern of each annihilation γ can be exploited for further precision potential comprehensive upon reconstruction. This is the same principle of the so-called “Compton Cameras“. The LPET fast readout articulation is also a mere extrapolation of the neutrino-based detector definition in the current exploration during prototyping. This enables the possible use of ortho-positronium (OPS); also proposed within the same framework. The OPS formation is a common articulation in neutrino detectors, as demonstrated in the Double Chooz experiment [“Ortho-Positronium Observation in the Double Chooz Experiment”, JHEP 1410 (2014) 032; also available at arXiv:1407.6913]. This same study OPS identification using pulse-shape discrimination sets a low limit on the pile-up capabilities of LiquidO, where discrimination is possible for deposition distance of approximately ~10ns apart. LiquidO will, additionally, articulate mm-level position or energy resolution (≤10% resolution) hence adding other handles for possible pile-up enhancement and discrimination, even without pulse-shape information.
The formation of the consortium (Nov.-Dec. 2021) followed an inter-IJCLab collaboration via the synergy of the IJCLab’s high energy and medical physics divisions. The consortium was further reinforced with the addition of key renowned experts in three main fronts: LiquidO instrumentation by Subatech (CNRS), PET-imaging by IPHC (CNRS) and LATIM (INSERM), and specialised source expertise by Arronax (CNRS). Thus, this constitution represents today’s LPET consortium. The first LPET demonstrator detector is the main goal behind the ANR (France) funding, coordinated by A. Cabrera since early 2022.