Speaker
Guido Haefeli
(Ecole Polytechnique Federale de Lausanne (CH))
Description
Silicon photomultipliers (SiPMs) are solid state photo detectors that combine all of the features necessary for
the photon detection of a high resolution scintillating fibre tracker. Two SiPM manufacturers, Hamamatsu and KETEK have
developed customized devices for SciFi Tracker application in the context of the LHCb tracker upgrade. These custom devices
provide high photon detection efficiency (PDE) in a large wavelength range, high reliability due to its simple mechanical
construction, a high density multi-channel package and are of sufficiently low cost to build a large area tracking device.
There are several challenging requirements placed on the photo-detector mainly due to the neutron radiation environment and
the low light output of the long scintillating fibre modules. New devices with the latest technological improvements
implemented are available in spring 2014. This includes devices with different optical isolation between pixels (trenches)
and different pixel sizes. The dark noise rate (DCR) increases strongly with irradiation and the noise cluster rate of the
tracking device can only be kept sufficiently low at a temperature of -40°C. We present the results on PDE, cross-talk
and noise before and after neutron irradiation at various temperatures. The results are compared for the latest and the
devices based on the standard technology.
Primary author
Guido Haefeli
(Ecole Polytechnique Federale de Lausanne (CH))
Co-author
Fred Blanc
(Ecole Polytechnique Federale de Lausanne (CH))
