Open-source hardware and cost-effective gamma-ray spectrometer using Raspberry Pi Pico

Abstract

This work presents the development and evaluation of the OpenGamma spectrometer, an open-source, compact and cost-effective gamma-ray detection system built on a Raspberry Pi Pico board. Data acquisition was performed using a GAGG scintillation crystal coupled with a Silicon Photomultiplier (SiPM). The background count rate was 5.24 counts per second. The system was evaluated with standard radioactive sources, achieving an energy resolution of 7.6% at 662 keV, which is comparable to other low-cost gamma spectrometers. The energy calibration curve exhibited a slightly quadratic behavior, typical for scintillation detectors. The dead time was estimated at 39.9 ± 3.9μs, reflecting the system’s capacity to process signals with minimal loss. The Gamma MCA web application further enhances the usability of the spectrometer by providing a user-friendly interface for data acquisition and analysis. The OpenGamma spectrometer offers a promising solution for applications in education, research, and field deployment. Future work will focus on improving its energy resolution and dead time to expand its use cases.