The equivalent volume method for gamma spectrometry calibration: A new method bridging the gap between distributed...

Area of Science:

• Nuclear Physics
• Analytical Chemistry
• Environmental Science

Background:

• Standard reference materials for gamma spectrometry calibration are costly and scarce.
• This limits customized efficiency calibration for accurate activity determination.

Purpose of the Study:

• Introduce the Equivalent Volume Method (EQVM) for gamma spectrometry calibration.
• Reduce reliance on standard reference materials and enable customized calibration.

Main Methods:

• Utilized point sources and a defined "Equivalent Volume" within Genie 2000 software.
• Conducted experiments with diverse environmental matrices and cylindrical geometries.
• Developed theoretical models to support experimental findings.

Main Results:

• Established a constant scaling factor (F≈0.35±0.02) for equivalent volume determination, independent of energy, density, and matrix.
• Observed proportionality between self-absorption and linear attenuation coefficients.
• Achieved agreement within 1.5% deviation compared to certified materials.

Conclusions:

• EQVM is a precise, flexible, and economical alternative for gamma spectrometry calibration.
• Enables accurate activity determination without matrix-specific corrections.
• Provides a physics-based criterion for validating efficiency correction models.