Long-Range Imaging of Alpha Emitters Using Radioluminescence in Open Environments: Daytime and Night-Time...

Area of Science:

• Nuclear Physics and Radiation Detection
• Environmental Science and Monitoring
• Optical Engineering

Background:

• Alpha emitters pose significant health risks (DNA damage, cancer) upon ingestion.
• Conventional detection methods necessitate close proximity, creating safety hazards and inefficiencies.
• Long-range alpha radioluminescence (RL) detection is a promising but challenging alternative, especially in ambient light.

Purpose of the Study:

• To demonstrate the feasibility of long-range alpha emitter detection in open, real-world environments.
• To develop and validate a compact alpha camera system capable of overcoming ambient light interference.
• To establish the detection limits and operational range of the alpha camera under various lighting conditions.

Main Methods:

• Utilized a compact alpha camera with a deep-cooled CCD and a low f-number lens system.
• Employed a dual-filter system (337 nm and 343 nm) for night-time alpha RL detection and background light subtraction.
• Implemented a stack of tilted 276 nm short-pass filters for daytime detection under simulated urban lighting.

Main Results:

• Successfully detected a 3 MBq alpha source from 1 meter away in one minute during night-time imaging.
• Achieved a lowest detection limit of 75 kBq for alpha emitters.
• Enabled detection of the alpha source at 70 cm within 10 minutes under indirect sunlight during daytime simulations.

Conclusions:

• The developed compact alpha camera is viable for long-range optical detection of alpha emitters in open environments.
• The system effectively mitigates ambient light interference for both day and night-time monitoring.
• This technology offers a significant advancement for environmental monitoring and radiation safety applications.