Development of a global rainbow refractometry technique to measure the temperature of spray droplets in a large containment vessel

In order to study the heat and mass transfers between a spray of droplets and the atmosphere in thermal-hydraulics conditions representative of a severe accident in a Pressurized Water Nuclear Reactor, the French Institute for Radioprotection and Nuclear Safety (IRSN) developed the TOSQAN facility. The present paper presents the development and the quantification of an optical diagnostic, global rainbow refractometry, in order to measure falling droplet temperature.