F. Suarez

Analog multiplexer for testing multianode photomultipliers used in AMIGA project of the Pierre Auger Observatory

Most particle detectors used in astroparticle physics have an optoelectronic device that senses generated light and converts it into an electrical pulse. Photomultiplier tubes are commonly used, particularly those with multiple anodes. Prior to coupling to a detector system these tubes must be fully characterized, which requires either the same number of data acquisition channels as outputs or a switching-multiplexer system. Given that every project has its own requirements, the testing system must be as flexible as possible. The multiplexer presented here can be used to test silicon photomultipliers or any high-frequency signal. It is a scalable 64 to 4 channel analog device designed for low crosstalk and low attenuation. Results of the application of this multiplexer with a −3 dB bandwidth of 800 MHz are shown by testing 64-channel tubes for the AMIGA project.

Silicon photo-multipliers characterization system

Silicon photo-multipliers (SiPMs) are currently progressively replacing photo-multipliers tubes (PMTs) in most applications due to their technical advantages, specially in high energy physics experiments. This work describes a system to test photo-detectors in order to calibrate and characterize the parameters generally defined by scientific projects requirements. The system controls and monitors different variables, as temperature, bias, controlled light-source emission, and chamber humidity. It is included in this document the calibration results for a SensL MicroFC-SMA-30035 SiPM and its operation under working thermal conditions, such as the expected for an atmospheric Cherenkov telescope detector. First results show that the usage of this SiPM in a telescope is feasible concerning the expected thermal excursion.