Abstract

• The main objective of this research work is to construct and analyze the photodiode based active detector for radon detection in air. It was intended to operate in pulse counting mode for real-time measurements. The constructed system is relatively simple, low-cost and reproducible, made of inexpensive and easy to acquire electronics components. The commercial low-cost Si-PIN planar photodiode SLCD-61N5 with an area of 10  10 mm2 was used as a sensor for detection of alpha particles. An ATmega2560 microcontroller (MCU) based Arduino MEGA development was interfaced to the electrical circuit of the device to count the logic pulses and connected to a computer to send and save the detected data. Electrical pulse signals corresponding to the strike of the alpha particles on the photodiode, distinguishable from noise, were observed in the radon detection analysis. It was observed that the sensitivity response of the constructed system increased with a higher reverse voltage applied to the photodiode. The stability of the constructed radon detector was also analyzed for long-term measurements. It could be said that the constructed system detected the presence of radon gas in order to obtain exact concentrations values in air.