Development Of Ring-imaging Cherenkov Counter For Heavy Ions

Up to this day, RICHes have been mainly used for high energy experiments to identify leptons and mesons. On the other hand, the number of Cherenkov photons is proportional to square of the atomic number, so that application of a RICH for heavy ions is expected. Then we are developing a ring-imaging Cherenkov counter for heavy ions (HI-RICH). The experiment was performed at NIRS-HIMAC. As for the primary beam ($^{132}$Xe with an energy of 420 MeV/u), a velocity resolution $\Delta\beta/\beta=0.050\%$ (standard deviation $\sigma$) and a detection efficiency $\varepsilon=99.9\%$ were achieved. Regarding to the secondary beam, a particle identification was successfully performed with HI-RICH and an ion chamber.