CERN Accelerating science

Article
Title	CO2 cooling for HEP experiments
Author(s)	Verlaat, B (NIKHEF, Amsterdam) ; Van Beuzekom, M (NIKHEF, Amsterdam) ; Van Lysebetten, A (NIKHEF, Amsterdam)
Publication	CERN, 2008
In:	Proceedings of the Topical Workshop on Electronics for Particle Physics, pp.328-336
DOI	10.5170/CERN-2008-008.328
Subject category	Detectors and Experimental Techniques
Abstract	The new generation silicon detectors require more efficient cooling of the front-end electronics and the silicon sensors themselves. To minimize reverse annealing of the silicon sensors the cooling temperatures need to be reduced. Other important requirements of the new generation cooling systems are a reduced mass and a maintenance free operation of the hardware inside the detector. Evaporative CO2 cooling systems are ideal for this purpose as they need smaller tubes than conventional systems. The heat transfer capability of evaporative CO2 is high. CO2 is used as cooling fluid for the LHCb-VELO and the AMS-Tracker cooling systems. A special method for the fluid circulation is developed at Nikhef to get a very stable temperature of both detectors without any active components like valves or heaters inside. This method is called 2-phase Accumulator Controlled Loop (2PACL) and is a good candidate technology for the design of the future cooling systems for the Atlas and CMS upgrades.