Vertical drift chimneys, digitisation, CRPs

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 wires to collect the signals of the electrons, originating from charged particles’ ionization, at the end of their drift path. This kind of development program, included in task 9.3, is unprecedented and innovative in the domain of LAr Time Projection Chambers (TPC). In Vertical Drift the wire planes are replaced by stacks of perforated printed circuit boards integrated in Charge Readout Planes (CRP) with an area of  3 x 3.3 m² , covering the surface at the top and bottom of the detector. This active surface receives the electrons drifting thanks to a uniform electric field aligned along the vertical axis.  Task 9.3 focuses on the readout of the top-drift volume of the detector. 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 outside during detector operation. The digitization electronics on the detector roof is cabled to warm-flanges closing the top part of the chimneys. This technology, which is foreseen to equip a DUNE Far Detector module, underwent extensive large-scale tests at the CERN Neutrino Platform in 2021-2022. These tests successfully demonstrated its validity. During 2024 all these technologies reached development maturity ready for production and passed the DUNE Production Readiness Reviews. This deliverable document reports about the overall work and developments performed on the CRP readout system for the DUNE Vertical Drift Far Detector module which is currently in construction.