München 2019 – wissenschaftliches Programm
HK 54.70: Poster
Donnerstag, 21. März 2019, 16:30–19:00, Foyer Theresanium
Charge density as a driving factor for discharges in THGEM-based detectors — •Lukas Lautner, Berkin Ulukutlu, and Piotr Gasik — TU München, Physik Department E62, Excellence Cluster ’Universe’, Garching
Thick Gas Electron Multipliers (THGEMs) are robust, high gain gaseous detectors with a structure resembling a GEM with expanded dimensions. Electrical discharges during operation of THGEM-based detectors may result in detection dead time, efficiency loss and damage to hardware and electronics. Although there are measures to minimize the discharge probability, discharges cannot be completely avoided.
These discharges are triggered by charge densities close to the Raether limit (106-107 electrons) in single THGEM holes.
Discharge probability curves for THGEMs in different Ar- & Ne-based gas mixtures have been measured. A comparison with GEANT4 simulations allowed to extract the critical charge density leading to the formation of a spark in a THGEM hole. It occurs that this number depends on the gas mixture and is a driving factor for discharge formation in THGEM-based detectors.
This research was supported by BMBF, HGF and the DFG cluster of excellence Origin and Structure of the Universe.