Portable spectrometry system for gamma radiation embedded in an ARM Cortex-M7 MCU

The use of digital systems in nuclear sciences has increased in recent years in the different areas that comprise it, such as detectors, spectrometry, spectroscopy, simulation, etc. The use of radioactive material always carries an inherent risk for personnel, for this reason it is necessary to have a precise classification and quantization of the radiation, for this is necessary, in addition to a radiation detector, a multichannel analyzer which is the spectrometry par excellence that separates the different pulse heights of the incident radiation into different channels, obtaining useful information about the radiation. This manuscript presents the design and implementation of a low-cost, fully portable multichannel analyzer for nuclear (in situ) spectrometry. The development is based on a 32-bit micro controller with ARM Cortex-M7 architecture (STM32-H745-XIH6), this design is capable of digitizing and analyzing pulses coming from a radiation detector without the need to transform the input signal with any filter, obtaining the maximum height of each of the digitized pulses, segmenting the information into channels to form a histogram and displaying the LCD screen incorporated in the system or in the application developed for the computer. A continuous digitization methodology was used, which is carried out by the DMA and an ADC with a resolution of 12 bits at a speed of 3.6 MSPS. The system is more economical than the commercial one, has a compact design, has low energy consumption and can open and save spectra in an SD memory integrated into the system. The multichannel analyzer implemented in the MCU was tested with a NaI(Tl) scintillation radiation detector, which made it possible to determine that the spectra obtained are similar to commercial multichannel analyzers. The results obtained show that the MCA in MCU is efficient for nuclear spectrometry, in addition to being very economical and with low energy consumption. (author)