Simulation Study of Photon-to-Digital Converter (PDC) Timing Specifications for LoLX Experiment

• Published in: arXiv.org 2023-10
• Main Authors: Viet, Nguyen V H, Alaa Al Masri, Nomachi, Masaharu, Marc-Andre Tétrault, Soud Al Kharusi, Brunner, Thomas, Chambers, Christopher, Chana, Bindiya, Austin de St Croix, Egan, Eamon, Francesconi, Marco, Gallacher, David, Galli, Luca, Giampa, Pietro, Goeldi, Damian, Lefebvre, Jessee, Malbrunot, Chloe, Margetak, Peter, Martin, Juliette, McElroy, Thomas, Patel, Mayur, Rebeiro, Bernadette, Retiere, Fabrice, Rtimi, El Mehdi, Rudolph, Lisa, Viel, Simon, Xie, Liang
• Format: Article
• Language: English
• Subjects: Parameters; Photons; Scintillation counters; Separation; Simulation; Simulation models; Specifications; Xenon
• ISSN: 2331-8422

The Light only Liquid Xenon (LoLX) experiment is a prototype detector aimed to study liquid xenon (LXe) light properties and various photodetection technologies. LoLX is also aimed to quantify LXe's time resolution as a potential scintillator for 10~ps time-of-flight (TOF) PET. Another key goal of LoLX is to perform a time-based separation of Cerenkov and scintillation photons for new background rejection methods in LXe experiments. To achieve this separation, LoLX is set to be equipped with photon-to-digital converters (PDCs), a photosensor type that provides a timestamp for each observed photon. To guide the PDC design, we explore requirements for time-based Cerenkov separation. We use a PDC simulator, whose input is the light information from the Geant4-based LoLX simulation model, and evaluate the separation quality against time-to-digital converter (TDC) parameters. Simulation results with TDC parameters offer possible configurations supporting a good separation. Compared with the current filter-based approach, simulations show Cerenkov separation level increases from 54% to 71% when using PDC and time-based separation. With the current photon time profile of LoLX simulation, the results also show 71% separation is achievable with just 4 TDCs per PDC. These simulation results will lead to a specification guide for the PDC as well as expected results to compare against future PDC-based experimental measurements. In the longer term, the overall LoLX results will assist large LXe-based experiments and motivate the assembly of a LXe-based TOF-PET demonstrator system.