The study of Electrical Arcing in ProtoDUNE High Voltage System

The Deep Underground Neutrino Experiment (DUNE) will be a leading-edge neutrino experiment based on Liquid Argon Time Projection Chamber (LArTPC) technology. The prototype for the far detector, called ProtoDUNE, is hosted at CERN. The research and development of ProtoDUNE will ensure the achievement of detector specifications and streamline the construction of the DUNE far detectors. The high voltage system ensures a uniform electric field and electrical stability, which is critical for the operation of the detector. The instability of the high voltage systems is caused by random electrical arcing inside the active volume of the detector. The duration of an arc is typically on the millisecond scale and varies with the intensity of the current spike, which can reach up to 200μA. The study of the current and voltage variations inside the detector allows us to pinpoint the time and location of electrical arcs, helping the identification of design flaws or defective elements of the detectors. Complimentarily, we are mapping the heat flow inside the detector during the arcing period to understand the causes of these instabilities better. Heat flow is much more convenient to study because it comes as a residue of the arcing and persists longer than a few ms. Here we present results on both methods of studying TPC instability.