Simulation study of a simultaneous beta-gamma-ray detection using a 3-layer phoswich detector and Monte Carlo methods

Area of Science:

• Nuclear Instrumentation
• Radiation Detection and Measurement

Background:

• Radiation detectors are crucial for environmental monitoring.
• Discriminating between beta and gamma radiation is essential for accurate analysis.

Purpose of the Study:

• To design and evaluate a three-layer Phoswich detector for beta-gamma discrimination.
• To implement a simple rise-time method for efficient event separation.

Main Methods:

• Utilized MCNPX Monte Carlo code for optimizing detector layer thicknesses and interaction probabilities.
• Simulated optical transport using GEANT4.
• Employed rise-time discrimination to separate beta and gamma events.

Main Results:

• Successfully discriminated beta events (rise-time < 9 ns) from gamma-ray events (rise-time > 15 ns).
• Achieved minimal gamma-ray contamination in the beta spectrum.
• Enabled recording of individual beta or gamma spectra from mixed sources.

Conclusions:

• The proposed three-layer Phoswich detector with rise-time discrimination is effective for environmental radiation monitoring.
• This method allows for accurate separation of beta and gamma radiation from simultaneous emitters.
• The system minimizes cross-contamination, improving spectral analysis accuracy.