STM32F407 microcontroller based multichannel analyzer for spectroscopy

Abstract

 The multichannel analyzer (MCA) is a crucial device for recording and analyzing radiation energy spectra to ascertain energy and intensity. It can be implemented via FPGA with a fast ADC and digital algorithm or a microcontroller with a peak detector circuit using an analog electrical circuit. MCA is widely applied in field work, nuclear medicine, and accelerator experiments. This work focuses on developing a lowcost alpha and gamma spectrometric system for experimental physics and field work, such as recording radiation and monitoring nuclear facility surroundings. Modern microcircuits, with small size and low power consumption, enable simpler and cheaper analog signal processing circuits that process signals in real-time without digital conversion delays. The spectrometric amplifier (SA) and peak detector (PD) were modeled and prototyped. A Python-based real-time data acquisition program was developed. Signals are recorded on the STM32F407 microcontroller’s ADC and transmitted via USB to a PC. An experiment obtaining the Ra226 alpha source spectrum verified the MCA’s functionality. It is valuable for environmental radioactivity field work and student teaching.