R&D status of a gas-compressor based two-phase CO2 cooling system for FPCCD Vertex Detector

Fine pixel CCD (FPCCD) is one of the candidate sensor technologies for the vertex detector used for experiments at the International Linear Collider (ILC). FPCCD vertex detector is supposed to be cooled down to -40 degree for improvement of radiation immunity. For this purpose, a two-phase CO2 cooling system using a gas compressor for CO2 circulation is being developed at KEK. The status of this R&D is presented in this article.