The compact disk as radon detector--a laboratory study of the method

Area of Science:

• Environmental Science
• Nuclear Physics
• Materials Science

Background:

• Radon-222 (Rn-222) is a radioactive gas found indoors, posing health risks.
• Accurate retrospective detection methods are needed for long-term radon monitoring.
• Polycarbonate materials exhibit properties suitable for radiation detection.

Purpose of the Study:

• To evaluate commercial compact disks as retrospective detectors for radon-222.
• To investigate the influence of environmental factors (pressure, temperature, humidity) on detector response.
• To develop a method for correcting temperature-induced biases in radon measurements.

Main Methods:

• Utilizing the track etch properties of polycarbonate compact disks.
• Removing a surface layer to access alpha particle tracks from radon progenies at specific depths (>80 microm).
• Experimental analysis of detector response under varying pressure, temperature, and humidity conditions.

Main Results:

• Detector response is largely unaffected by pressure and humidity (within 10% variation).
• Temperature variations (15-25°C) cause a +/-12% response change at 83 microm depth.
• Depth-dependent calibration factors show exponential behavior influenced by temperature.

Conclusions:

• Retrospective radon-222 measurements using compact disks can achieve <10% uncertainty with temperature correction.
• A posteriori temperature correction, using track densities from multiple depths, significantly reduces bias.
• The method is effective for long-term indoor radon monitoring, covering concentrations from 3 Bq m⁻³.