TIPP 2011 - 2nd International Conference on Technology and Instrumentation in Particle Physics

High gain hybrid photomultipliers based on solid state p-n junctions in Geiger mode and their use in astroparticle physics.

Not scheduled

1m

Sheraton Hotel (Chicago)

Poster Presentation Photon Detectors

Speaker

Dr Daniele Vivolo (INFN)

Description

In astroparticle physics photomultiplier tubes play a crucial role in the detection of fundamental physical processes. After about one century of standard technology (photocathode and dynode electron multiplication chain), the recent strong development of modern silicon devices has brought to maturity a new generation of photodetectors based on an innovative, high-quality, cost effective technology. In particular the most promising development in this field is represented by the rapidly emerging CMOS p-n Geiger-mode avalanche photodiode technology (G-APD or SiPM), that will allow the detection of high-speed single photons response with high gain and linearity. Most applications will require collection of light from even larger surfaces or volumes, so it is necessary to increase the active surfaces and the angular covertures of SiPMs while keeping high sensitivities. The main purpose of this research is, therefore, to offer an attractive response to overcome this problem. The idea is to realize an hybrid detector (Vacuum Silicon PhotoMulTiplier,VSiPMT), where the dynodes structure of a classical Vacuum PhotoMultiplier Tube (VPMT) is replaced by an array of G-APDs, which collects the photoelectrons emitted by a photocathode and acts as an electron multiplier. As a possible future development, the exploitation of the full fill factor of a front illuminated SiPM, in which quenching resistors and electric contacts are integrated in the bulk, could allow the full geometrical efficiency of a SiPM used as an amplifying element. In this way this hybrid PMT will result equivalent to those already existing manufactured with APD (gain 102), but with a gain comparable to the standard PMTs (106-107). Such an amplifier would be free of such intrinsic limitations of classic photomultipliers as: limited linearity due to high gain, no capability for precise photon counting, complexity of construction, sensitivity to magnetic fields and faults in cryogenic environments. On the other hand it would present several attractive features such as: small size, low cost, high gain, high efficiency, absence of an external voltage divider, no power consumption, weakened dependence on magnetic fields.