Speaker
Davide Pinci
(ROMA1)
Description
When using detectors made of a crystal and a photo-detector in high rate applications it is not always possible to integrate the whole signal, the integration time being dictated by the need to avoid in the read-out the pile-up due to the large background of low energy particles.
By means of both experimental data on a BGO crystals and simulation, we developed a technique to compute the fraction of the emitted photo-electrons that participate to the formation of the signal up to its maximum ($F_{int}$). We demonstrate that when the number of photo-electrons is large the energy resolution scales as $1/\sqrt{F_{int}}$. We also show that when the number of photo-electrons is small the resolution is even better than the Poisson fluctuations.
Finally we detail the case of BGO. It is considered as an option for the forward calorimeter of the SuperB experiment and it would, in this case, need to be read with an integration time as small as 100 ns, i.e. one third of the decay time of its scintillation. Our measurements demonstrate that in this configuration the loss of energy resolution is absolutely tolerable and that therefore BGO is an attractive possibility for equipping calorimeters also in very high rate experiments.
Primary author
Riccardo Faccini
(INFN - Roma 1)
Co-author
Davide Pinci
(ROMA1)
