Speaker
Description
Summary
Modern $e^{+} e^{-}$ factories with high luminosity require fast response time of the detector subsystems to suppress severe beam background. Crystals of pure CsI (CsI(pure)), with a scintillation decay time of 30 ns, allow one to reduce substantially pileup noise in the electromagnetic calorimeter. We discuss the prototype of the electromagnetic calorimeter consisting of 16 counters. Each counter consists of CsI(pure) crystal (6 $\times$ 6 $\times$ 30 cm$^3$), wavelength shifter (WLS)
plate (6 $\times$ 6 $\times$ 0.8 cm$^3$) with the nanostructured organosilicon luminophores (NOL-9), four avalanche photodiodes (APD)
Hamamatsu S8664-55 and four-channel charge sensitive preamplifier, see Fig.~1(a). The optimization of the shape of the WLS plate has been carried out to improve the signal. The basic characteristics of all counter's components have been measured. The signals from the counters are processed by four four-channel shaper-ADC boards with the signal waveform sampling. The prototype is under the assembling procedure now, see Fig.~2.\
By the end of February, we plan to obtain the first result of cosmic particle registration by a prototype.
Fig.1
Scheme of the counter: APDs are coupled to the truncated corner
edges of the WLS plate
