Efficiency and uniformity measurements of a light concentrator in combination with a SiPM array

A position sensitive Cherenkov detector was built, consisting of 64 SiPMs with an active area of 3×3 mm2 and a pixel size of 100×100μm2. The sensitive area is increased by a light concentrator which consists of 64 pyramid-shaped funnels. These funnels have an entrance area of 7×7 mm2 and an exit area of 3×3 mm2, guaranteeing a sufficient position resolution e.g. for the barrel DIRC detector of the PANDA experiment at FAIR. The efficiency and uniformity of the light concentrator in combination with the SiPM array was tested by scanning the array in two dimensions, using a pulsed light beam. Results of these tests and comparison with simulations are given here.