Dortmund 2021 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 72: Experimental techniques in astroparticle physics III

T 72.1: Talk

Wednesday, March 17, 2021, 16:00–16:15, Tv

PMT afterpulse studies in XENONnT — •Luisa Hötzsch for the XENON collaboration — Max-Planck-Institut für Kernphysik, Heidelberg

The XENONnT detector is the next generation direct dark matter detector in the XENON experiment series, utilizing in total 8.4 tonnes of xenon in a dual-phase liquid xenon time projection chamber. The scintillation light produced by particle interactions in the xenon target is detected by 494 Hamamatsu R11410-21 photomultiplier tubes (PMTs), chosen for their high quantum efficiency and low intrinsic radioactivity. One of the main PMT-intrinsic backgrounds is the effect of ion afterpulsing. Due to their typically short delay times of up to only a few microseconds, afterpulses can seriously impact the data quality in rare event searches. In particular, increasing afterpulse rates caused by a gradual vacuum degradation in the PMT can induce time-dependent background effects. In this talk I will present studies on the ion afterpulses in the XENONnT PMTs, using in-situ LED data taken during the XENONnT commissioning phase, as well as the afterpulse monitoring tools developed for future science data runs of XENONnT.