Development of an air cooling system with low material budget for high-energy physics applications

This work presents the cooling system of a future particle detector at the Large Hadron Collider (LHC): the Inner Tracking System 3 (ITS3) of the ALICE experiment. Efficient cooling is crucial for maximizing the particle measurement quality in the LHC. The system introduces open-cell carbon foams as heat exchangers that combine heat conduction and convection for the first time in a high-level engineering application. The system is designed to have an unprecedentedly low material budget, which is a requirement for particle detectors aiming at precise tracking at low particle momenta. This novel approach leads to a 80% reduction of the material budget compared to the previous version (ITS2), resulting in enhanced measurement accuracy. The study employs an experimental wind tunnel setup and numerical simulation, showing excellent agreement with mean deviations under 0.5 K that are attributed to sensor installation uncertainties. The results confirm the system adherence to the temperature requirements. Compared to the baseline design, it is shown that enhancements based on numerical simulations produce potential reductions of up to 50% in the maximum temperature variation of the detector layers.