EGU25-13183, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-13183
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Development of an active alpha particle detector for radon measurements
Tóth Szabolcs1, Horváth Ákos1, and Máthé Kálmán2
Tóth Szabolcs et al.
  • 1Eötvös Lóránd University, Institute of Physics and Astronomy, Atomic Physics Department, Budapest, Hungary
  • 2University of Pécs, Faculty of Engineering and Infromation Technology, Institute of Engineering and Smart Technologies, Department of Electrical Engineering, Pécs, Hungary

In connection with the recultivation and environmental monitoring activities of the Mecsek uranium ore mine closure, several deep boreholes have been drilled. These deep boreholes are suitable for investigating spatial and temporal variations of radon activity concentrations. Measurements require a large number of radon sensors with data loggers.

Our goal was to develop an inexpensive device with commercial photodiode for counting the alpha particles (in particular radon and its daughter elements). The principal operation of the developed monitoring system is based on the following steps: when a charged alpha particle hits the sensitive area of the sensor a small current is generated with amplitude proportional to the deposited energy. This current signal is converted into a voltage signal by a charge-sensitive preamplifier and amplified in several steps. Then the analogue signal is converted to digital by a comparator, and an ATmega328 microcontroller with a DS3231 RTC module is used to count and store the pulses. The alpha spectral response of the device has been calibrated by using 241Am solid source. Additionally, numerous tests were carried out in experimental chamber, with uranium ore sources. The developed detector was tested with several diffusion chambers with various sizes for soil gas and dwelling measurements, and determination of radon exhalation rate. Prototypes are currently being tested in deep boreholes, and in recultivated areas.

How to cite: Szabolcs, T., Ákos, H., and Kálmán, M.: Development of an active alpha particle detector for radon measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13183, https://doi.org/10.5194/egusphere-egu25-13183, 2025.