Paolo Petagna (CERN)
For future Vertex detectors, where the requirements on material budget minimization and performance optimization will push at the limit the design and technology choices, thermal management solutions based on ultra-thin micro-channel heat exchangers are being envisaged. The NA62 GTK detector, launched in operation at the end of 2104 has demonstrated for the first time the practical feasibility of the direct cooling of a pixel detector module by a micro-fabricated silicon device circulating single-phase liquid refrigerant. The very advanced studies in preparation of the “phase-I” upgrade of the LHCb VELO detector (detailed in a separate presentation) suggest that the thermo-physical characteristics of CO2 are very favourable for its use in connection with evaporative flow in micro-channel devices. On the other hand, a recently presented study on a possible application of this technology to the upgrade of the ALICE ITS detector provided the first demonstration of two devices hydraulically interconnected through an integrated micro-fluidic distribution line, allowing for controlled evaporation of C4F10 in both micro-devices. Starting from these achievements, the presentation will review the latest technical progresses and the open issues to be addressed in view of the challenges posed by the next generation of detectors. Different lines of investigations will be discussed, in particular in view of the 4-years networking activity to be soon launched in the context of the recently approved AIDA-2020 programme; and different options will be examined from a detector engineering point of view. Finally, some preliminary ideas will be presented for long-term developments, requiring a level of technology not available today for operational implementation, yet ready for interesting early feasibility studies.