Chapter 5: Two-Phase Thermal Management of Silicon Detectors for High Energy Physics

The peculiar characteristics of modern silicon detectors for High Energy Physics experiments make their effective thermal management challenging. Although the electronics chips are designed for very low power consumptions, the large number of sensors concentrated in a confined volume in convoluted geometries creates a power dissipation per unit volume comparable to the one of the most demanding high power electronics applications. This, added to a hostile environment and to very specific requirements of mass minimization, pushes the thermal design toward the adoption of advanced technologies. Among these, two are particularly interesting in terms of two-phase flow applications. The first one is the use of very stable and precisely controlled evaporative CO₂ flows in multi-meter long evaporators of small internal diameter. The second one is the development of microstructured multichannel evaporators directly fabricated in silicon, for a perfect matching with the sensors and their related electronics. This chapter provides a detailed overview of the most recent advances in these fields aiming to the highest efficiency for future detector thermal management systems.