Laboratory facility to create reference radon + thoron atmosphere under dynamic exposure conditions

Area of Science:

• Environmental Science
• Nuclear Physics
• Metrology

Background:

• Radon (Rn-222) and thoron (Rn-220) exhibit significant environmental variability.
• Accurate detectors and research require reproducible laboratory exposure conditions.

Purpose of the Study:

• To design and present a novel laboratory facility for controlled radon and thoron exposure.
• To enable testing of Rn-222 and Rn-220 detectors under simulated environmental conditions.

Main Methods:

• Developed a facility for static and dynamic Rn-222 and Rn-220 activity concentrations.
• Integrated a programmable thermostat for temperature control (-15°C to +60°C).
• Regulated air flow rates to achieve desired Rn-222/Rn-220 activity concentrations and ratios.

Main Results:

• Successfully created reference atmospheres with pure Rn-222, pure Rn-220, or mixed gases.
• Demonstrated feasibility through pilot experiments, including temperature profiling and dynamic Rn-220 control.
• Validated experimental results against a theoretical model, showing good agreement for mixed Rn-222/Rn-220 ratios (0.27 to 4.5).

Conclusions:

• The facility provides a reliable method for creating stationary and dynamic reference exposure conditions.
• This approach supports accurate calibration and research for radon and thoron detection.
• The system effectively simulates real-world radon and thoron exposure regimes.