An anti-cosmic β-γ coincidence system for radioxenon measurement

Area of Science:

• Nuclear physics
• Environmental monitoring
• Radiochemistry

Background:

• High detection sensitivity is crucial for radioxenon measurements.
• Background radiation, particularly from cosmic-ray muons, can interfere with sensitive measurements.
• Existing beta-gamma coincidence systems require further performance optimization.

Purpose of the Study:

• To develop and implement an anti-cosmic detector system for a beta-gamma coincidence setup.
• To reduce background noise induced by cosmic-ray muons.
• To evaluate the performance enhancement of the upgraded radioxenon measurement system.

Main Methods:

• Integration of a cosmic-ray veto detector with a broad energy germanium gamma-detector and a plastic scintillator beta-detector.
• Setup and commissioning of the anti-cosmic beta-gamma coincidence system.
• 24-hour measurement campaign to assess system performance and background reduction.

Main Results:

• The anti-cosmic system effectively reduces background noise.
• Achieved Minimum Detectable Activity (MDA) for 131mXe: 0.9 mBq.
• Achieved MDA for 133mXe: 1.1 mBq, 133Xe: 2.2 mBq, and 135Xe: 2.1 mBq.

Conclusions:

• The implemented anti-cosmic system significantly enhances the detection sensitivity of the beta-gamma coincidence setup.
• The system demonstrates excellent performance for radioxenon monitoring with ultra-low MDA values.
• This advancement is critical for accurate environmental monitoring and nuclear event detection.