Status report on digitization

Task 9.3 foresees the study of a novel charge readout scheme for very large time projection chambers named Vertical Drift. This technology avoids using wire chambers to collect the signals of the electrons from charged particles ionization, at the end of their drift path. This kind of development program, included in task 9.3, is unprecedented and totally innovative in the domain of LAr Time Projection Chambers (TPC). In Vertical Drift wire chambers instead are replaced by stacks of perforated printed circuit boards integrated in Charge Readout Planes (CRP) of 3x3.3 m² placed to cover the surface at the top of the detector. This active surface receives the electrons drifting thanks to a uniform electric field aligned along the vertical axis. The cryogenic ASIC amplifiers used to read the signals are integrated in this layout in front-end cards hosted in cryostat penetrations ‘signal feedthrough chimneys” which make them accessible from the outside during detector operation. The digitization electronics at warm is cabled to warm flanges closing the top part of the chimneys. This technology, which is foreseen to equip the second DUNE Far Detector module, underwent in 2021-2022 extensive large-scale tests at the CERN Neutrino Platform. These tests successfully demonstrated its validity. This milestone reports on the work and developments performed on the CRPs readout system.