Development of prototype RICH detector with multi-anode photomultipliers for radioactive ions

摘要

RI-RICH, a ring-imaging Cherenkov counter for radioactive ions, has been developed to measure the velocity of the ions at intermediate energies. Our RI-RICH system consists of six multi-anode photomultiplier tubes covered with 360-nm bandpass filters and a radiator made of quartz or BK7. For the primary(132)Xe beam with a velocity of beta = 0.712, a velocity resolution of Delta beta/beta = 4.9 x 10(-4) (one standard deviation sigma) and a detection efficiency of more than 99.99% were achieved. For the secondary beams with Z = 44-55 and beta similar or equal to 0.70, we successfully performed particle identification using the B rho-Delta E-beta method. The velocity resolutions of RI-RICH for these nuclides were equivalent to a more than 6 sigma separation for the mass number.