DIY handheld gamma ray spectrometer based on Raspberry Pi Pico

Although Geiger counters can be used to detect amounts of radiation, and with some tricks can also differentiate between the three types of radiation (alpha, beta, and gamma), their use is limited in identifying radioactive materials. For this purpose, gamma-ray spectrometers come in handy.

Using a small custom PCB, a Raspberry Pi Pico microcontroller, and a scintillator, you can build your own gamma spectrometer! The required processing and multi-channel analyzer are all on board, so no external parts are needed, except something to view the data (with a screen). The detector uses a silicon photomultiplier tube (SiPM), rather than the common photomultiplier tubes more common in these types of DIY projects. This means the entire assembly is smaller and safer because no high voltage is required! Also, compared to projects like theremino, you don't strictly need a computer or even an external soundcard - everything is self-contained. You can take stand-alone measurements using just a USB power cord and save spectra securely to the Pico's flash memory, or connect to your PC via a Serial-over-USB connection.