v 1 1 7 Ju n 20 05 Time resolution of Burle 85001 micro - channel plate photo - multipliers in comparison with Hamamatsu R 2083

Time resolution of Burle 85001 micro-channel plate photo-multipliers in comparison with Hamamatsu R2083. Abstract The CLAS detector will require improvements in its particle identification system to take advantage of the higher energies provided by the Jefferson Laboratory accelerator upgrade to 12 GeV. To this end, we have studied the timing characteristics of the micro-channel plate photo-multiplier 85001 from Burle, which can be operated in a high magnetic field environment. For reference and comparison, measurements were also made using the standard PMT R2083 from Hamamatsu using two timing methods. The cosmic ray method, which utilizes three identical scintillating counters 2 × 3 × 50 cm 3 with PMs at the ends, yields σ R2083 = 59.1 ± 0.7 ps. The location method of particles from radiative source with known coordiantes has been used to compare timing resolutions of R2083 and Burle − 85001. This " coordinate method " requires only one counter instrumented with two PMs and it yields σ R2083 = 59.5 ± 0.7 ps in agreement with the cosmic ray method. For the micro-channel plate photomultiplier from Burle with an external amplification of 10 to the signals, the coordinate method yields σ 85001 = 130 ± 4 ps. This method also makes it possible to estimate the number of primary photo-electrons.