For the GlueX experiment we have been evaluating "Silicon Photomultipliers" from SensL.
This type of photodetector is immune to magnetic fields and requires only ~30 volts of bias, yet has a gain of 10⁶.

The green cube is Eljen EJ-260 scintillator, the shiny cylinder is an Am₂₄₁ alpha source, and the 3 x 3 mm active photodetection area can be seen through the top face of the scintillator. The SiPM includes a thermoelectric cooler to reduce its temperature to -20 degrees C.
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