  Rare event search experiments, such as those searching for dark matter and
observations of neutrinoless double beta decay, require ultra low levels of
radioactive background for unmistakable identification. In order to reduce the
radioactive backgrounds of detectors used in these types of event searches, low
background photosensors are required, as the physical size of these detectors
become increasing larger, and hence the number of such photosensors used also
increases rapidly. Considering that most dark matter and neutrinoless double
beta decay experiments are turning towards using noble liquids as the target
choice, liquid xenon and liquid argon for instance, photosensors that can work
well at cryogenic temperatures are required, 165 K and 87 K for liquid xenon
and liquid argon, respectively. The Silicon Geiger Hybrid Tube (SiGHT) is a
novel photosensor designed specifically for use in ultra low background
experiments operating at cryogenic temperatures. It is based on the proven
photocathode plus silicon photomultiplier (SiPM) hybrid technology and consists
of very few other, but also ultra radio-pure, materials like fused silica and
silicon for the SiPM. The introduction of the SiGHT concept, as well as a
feasibility study for its production, is reported in this paper.
