Low-cost active detectors for radon gas detection: some preliminary test results

Radon gas is a significant source of natural radiation exposure in humans. In this research, the responses of three different radiation detectors are compared by preliminary test results for Radon gas detection. First detector is a pulse-mode counter developed by using a BPW۳۴ photodiode. To amplify and read out the output signal of the photodiode, a charge-sensitive preamplifier, based on a two-stage TLC۲۷۲ operational amplifier is designed. In the following, a pulse counting circuit is implemented by using an ATmega۳۲ microcontroller. The second developed detector is a current-mode air ionization chamber working at low applied voltages, with output signal enhanced by a current amplifier BC۵۱۷ Darlington transistor, read out by an Arduino UNO module. Additionally, an alpha-sensitive Geiger-Mueller counter (model NT-۹۶۰, Novin Teyf) with a mica entrance window is employed as the third detector. Soil samples containing natural Uranium, in companion with all three detectors were sealed in a chamber to study the detector responses to different concentrations of Radon gas. Findings indicate that all three detectors exhibit an increasing response as the concentration of Radon gas is increased. In the viewpoint of measurement accuracy, the Geiger-Mueller counter provides more accurate results due to a higher count rate and lower statistical fluctuations, with a concentration curve giving the half-life of Radon acceptably. The ionization chamber is shown to suffer from low sensitivity due to its current-mode operation.

کلیدواژه ها:

Arduino-based ion chamber ، Geiger-Mueller counter ، Photodiode detector ، Radon gas monitoring