To date, many of my Cosmic Ray experiments and projects have relied on Geiger–Müller tubes or photomultipliers scintillator detectors. The issue with using these detectors is a limited life and high voltages between 380 to 2000V DC, which must also be low noise and regulated.

Solid state devices, particularly Si Pin Photodiodes, can measure gamma rays and have some energy resolution. They also come with issues and compromises, such as more complexity, noise, and small aperture size. But also have their benefits with low voltage, low power and greater longevity. This project aims to develop a relatively cost-effective detector to measure muons, time of flight and energy resolution.

There are low-cost of-the-shelf Pin Photodiodes, such as the BPW34F, featured in many DIY projects over the years. However, these require significant amplification, slow and noisy. So can only be practically used as a simple gamma counter with no energy resolution and a tiny aperture.

There are also specialist Photodiodes designed specifically for gamma-ray and x-ray detection, but these can be expensive and difficult to source in small quantities. So the next best candidate is the medium-range detectors, usually with a 10mm x 10mm aperture, which come with, and without a light shield. Current detectors I am testing include:

  • Manufacture First Sensor Part # 5014450 – has a visible light filter
  • Manufacture First Sensor Part # PS100B-7-CERPINE – has a visible light filter
  • Hamamatsu Part # S3590 – no visible light filter