Speaker
Description
Phase-2 CMS particle detectors require an order-of-magnitude increase in evaporative CO2 (2PACL) cooling capacity while operating roughly 20 °C colder than legacy systems. This requires large co-axial transfer lines, whose performance has a non-negligible impact on detector temperature. The associated relatively low CO2 saturation temperatures (<-35 °C), large transfer line diameters, and long routings – including about 20 m of vertical 2-phase up-flow – entail significant modelling uncertainties when relying on empirical correlations with limited validation in these ranges. We report preliminary measurements on a prototype Phase-2 CMS transfer line connected to the DEMO R&D CO2 cooling plant, and assesses the performance of 2-phase flow models used to size future CMS 2PACL cooling equipment.
