An innovative polyimide microchannels cooling system for the pixel sensor of the upgraded ALICE inner tracker

The ALICE Inner Tracking System (ITS) is the key detector for the study of heavy flavour production at LHC. In order to enhance the ALICE physics capabilities and the tracking performance, an upgrade has been planned for replacing the existing ITS in its entirety with seven new layers of monolithic silicon pixel detectors. A novel light cooling system for the ITS's innermost layer has been developed and fabricated. It consists of polyimide microchannels able to remove the power dissipated by the active electronics through forced convection of water coolant. The development, the construction, the mechanical-thermal characterization and the integration of this cooling system will be presented.