Equipment for testing of cooling loops - ATLAS Upgrade (Instrument Development)

The planned Atlas Upgrade silicon micro-strip detector system will employ an evaporative cooling system similar to the current system, but will utilize CO2 rather than fluorocarbon as the coolant gas in order to improve the heat transfer and coolant-to-wall heat transfer properties for small mass flows. This can be achieved due to the large latent heat capacity of CO2 relative to the existing fluorocarbon gas, however the utilization of this requires operating pressures far in excess of the current pressure system.

As such, with operating pressures in excess of 150bara, it is essential to provide adequate testing of cooling systems to prevent catastrophic failure of the cooling elements. Safety and integrity testing of prototype and final design cooling loops will made possible by the equipment provided by this funding and will demonstrate our strategies to deal with both CO2 coolant leakage and highlight other potential failure sources.

Direct beneficiaries of this research is the UK-ATLAS Upgrade Tracker Collaboration. The research data produced by this equipment will allow for further optimisation of current prototype cooling structure and will influence later design improvements by demonstration of long term reliability. Future use of research data produced by this equipment will disseminate through the ATLAS international collaboration and the wider particle physics instrument construction community, allowing the findings to be adapted to take advantage of low mass material improvements such as uses of Carbon Fibre Reinforced Plastics with embedded cooling cores.
Commercial research measurements are anticipated through the ability to construct test (with certification) of low mass pressure handling systems, these are particularly well suited to aerospace and space science who need long term reliability testing in harsh environments.