Circulation model for water circulation and purification in a water Cerenkov detector

Owing to its low cost and good transparency,highly purified water is widely used as a medium in large water Cerenkov detector experiments. The water circulation and purification system is usually needed to keep the water in good quality. In this work,a practical circulation model is built to describe the variation of the water resistivity in the circulation process and compared with the data obtained from a prototype experiment. The successful test of the model makes it useful in the future design and optimization of the circulation/purification system.     

Study of Tyvek reflectivity in water

Tyvek is widely used as the inner lining material of water Cherenkov detectors. Therefore, information about its optical properties plays an important role in the simulation and reconstruction of particles passing through water Cherenkov detectors. In this paper, a water tank experiment is performed to study the Tyvek reflectivity in water. The so-called UNIFIED model, which is an optical model of surface reflection in Geant4, is adopted to describe the Tyvek reflectivity. Two key optical parameters are obtained from a comparison between the measured data and a Monte Carlo simulation.