CACTUS VD: AN UPDATE

This presentation reports on the current progress of the CACTUS Vertical Drift (CACTUS VD) project, a new cryogenic facility developed for the large-scale testing of SiPM Flexi boards required for the DUNE FD2–Vertical Drift detector. After outlining the transition from the Horizontal Drift to the Vertical Drift design and the characteristics of the 20-SiPM Flexi boards, the talk describes the architecture, components, and functionalities of the CACTUS VD system: mechanical structure, warm and cold electronics, automatic LN₂ refilling system, and the integrated control software running on Raspberry Pi, Arduino, and a LabVIEW server. All hardware elements have been procured, while the main remaining effort concerns the completion of the LabVIEW control code. The facility will enable automated testing of approximately 5800 Flexi boards through I–V measurements at room and cryogenic temperatures, extended dark measurements, and thermal cycling. Installation will take place at the University of Milano Statale