Pop a Little Gamma Spectrometery Into Your Next Project with Mihai Cuciuc's Pomelo One
Modular radiation detection system aims to make gamma spectroscopy as accessible as Arduino.
Engineer Mihai Cuciuc, of Pomelo Instrumentation, is preparing to launch a crowdfunding campaign for the company's eponymous radiation detector — designed to make gamma spectroscopy as accessible as Arduino, he says.
"Pomelo is an accessible, embeddable spectroscopic radiation detector platform. Our aim is to make gamma spectroscopy more accessible, as Arduino did for embedded systems engineering," Cuciuc explains. "Pomelo is modular, making it easy to experiment with every aspect of radiation detection, with functionality split between three components: Pomelo Physics houses the detector, Pomelo Core has all supporting electronics for taking measurements and making them available, and Pomelo Zest is an Arduino-compatible board that adds a user interface, battery, and wireless connectivity. Together, these components form a complete hand-held instrument that we call Pomelo One."
The Pomelo One is designed to measure radiation sources in both counts per minute (CPM) and microsieverts per hour (uSv/h), complete with the iconic "click" you'd expect from a Geiger counter, but can also display gamma spectra — meaning it's possible to identify particular radioactive isotopes by looking for specific peaks in the chart, visible on the on-board display or via the unit's built-in web interface. Two units can be combined in "confidence mode," Cuciuc adds, making them suitable for the detection of cosmic muons or for educational experiments involving Compton scattering.
The modular system is based around the Espressif ESP32-C6-powered Pomelo Zest board, which includes a 128×32 bitmap LCD display, three buttons, and a buzzer for those all-important clicks, which connects to the Pomelo Physics module and its CsI(Tl) scintillator crystal, silicon photomultiplier, and temperature sensor via the Pomelo Core and its Microchip SAM L21 microcontroller. All three boards are to be released under an open source license, Cuciuc says, though at the time of writing only the Zest board had design files available with just schematics for the Core and Physics modules.
Cuciuc is planning to launch a crowdfunding campaign on Crowd Supply in the near future, with interested parties invited to sign up to be notified when it goes live. The currently-released source code and hardware design files are available on GitHub under the permissive MIT license.