Proto DUNE II module-0 installation at CERN

This is inside the protoDUNE cryostat, a prototype for international DUNE experiment. It is also the largest liquid-argon neutrino detector in the world with a volume close to 10x10x10m3, almost the size of a three-story house and the shape of a gigantic cube. The walls of the cryostat have this peculiar “waffle-like” shape to withstand thermal stress that occurs when the cryostat is filled with liquid argon at -200°C. On the ceiling, we can see two copper-colored panels called CRPs (Charge Readout Planes), the actual particle detectors. These are installed to the cryostat roof facing opposite to the cathode modules with some photosensors. The CRPs are the detectors, featuring 4 different layers of copper strips, printed on perforated PCBs. The first layer is a shielding, the second and third collect induction signals from the passage of the electrons, the fourth collects the electrons and gives the most important signal.