Effect of sample density in prompt γ-ray analysis.

Area of Science:

• Nuclear Physics
• Analytical Chemistry

Background:

• Prompt gamma-ray analysis (PGA) is a precise, non-destructive method used across various scientific fields.
• PGA accuracy can be compromised in hydrogenous samples due to neutron energy variations from scattering.
• Existing research links accuracy degradation to hydrogen content, but the role of hydrogen density is under-explored.

Purpose of the Study:

• To investigate the impact of hydrogen density on PGA measurement sensitivity.
• To quantify the accuracy degradation caused by varying hydrogen densities in samples.

Main Methods:

• Evaluated PGA measurement sensitivity using samples with identical hydrogen content but differing densities.
• Analyzed the relationship between hydrogen density and measurement sensitivity variations.

Main Results:

• Measurement sensitivity varied by over 30% solely due to differences in hydrogen density, even with constant hydrogen content.
• This density-dependent variation poses a significant challenge for PGA, which often requires accuracy within a few percent.

Conclusions:

• Hydrogen density is a critical, previously overlooked factor affecting PGA accuracy in hydrogenous materials.
• Similar phenomena may impact nuclear cross-section measurements involving neutrons and nuclides with large scattering cross-sections, with implications for astrophysics and nuclear energy research.