Purpose of experiment
The purpose of the exercise is to measure the activity of radon and radon progeny in an indoor environment. Radon is one of the products of the 238U decay chain and it is the only one in gaseous form, and therefore the only one that can escape the out of the Earth’s crust. Radon may represent a significant contribution to natural radiation exposure, especially in karstic terrain (for which Slovenia is renowned), and after smoking, is the second most important cause of lung cancer.
Outcome / What you will learn
Students will:
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discuss the formation of radon through radioactive decay and diffusion into the atmosphere;
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perform simple experiments to demonstrate the presence of radon by detection of alpha radiation;
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perform radon concentration measurements using the Kuznetz method, by filtering radon progeny from the air and subsequent gamma spectrometry measurement.
Execution
After a discussion on the formation of radon through radioactive decay and its diffusion into the atmosphere, students:
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capture radon progeny onto electrostatically charged balloons and measure the emitted alpha particles;
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perform radon concentration measurements using the Kuznetz method by:
- filtering radon progeny from the air onto filter paper using a vacuum cleaner
- gamma spectrometry measurements of the filter paper
- analysis of the recorded gamma spectrum
- determination of the radon concentration from the measured radon progeny activities
Exercise No. 14: Indoor radon measurements