Charge signal formation in the TPC Vertical Drift design of DUNE

Giant Liquid Argon Time-Projection Chambers (LArTPC) will be used for the far detectors of the next generation of neutrino oscillation experiment: Deep Underground Neutrino Experiment (DUNE). This work focuses on the design of the Vertical Drift module (DUNE-VD), where the chamber consists of two drift volumes separated by a central cathode. This novel anode enables the detection of the ionization electrons through two inductions views and a charge collection view. Extensive R&D has been carried out at CERN in the past years to optimize the VD anode design. In this paper, a numerical simulation of the signal formation based on the Shockley-Ramo’s theorem and the physics of charge carriers’ motion in liquid argon will be presented. Comparisons with radioactive sources data taken at CERN with prototypes will be shown. A good understanding of the collected signal shape and strength is essential to achieve the track reconstruction efficiency and the calorimetric measurement resolution needed by the DUNE experiment to study neutrino oscillations.