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Updated: Jul 28, 2026
14:11
Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis
Published on: March 29, 2016
Monte Carlo simulation of prompt gamma neutron activation analysis using MCNP code
C J Evans1, S J Ryde, D A Hancock
1Swansea In Vivo Analysis, University of Wales Swansea, UK.
Summary
Prompt gamma neutron activation analysis (PGNAA) offers direct total-body nitrogen measurement. Advanced Monte Carlo simulations improve accuracy by correcting for body shape and fat, reducing costs and dependence on patient physique.
Area of Science:
- Nuclear Physics
- Medical Physics
- Biomedical Engineering
Background:
- Prompt gamma neutron activation analysis (PGNAA) is a primary method for assessing total-body nitrogen.
- Reducing dependence on individual body habitus is crucial for accurate PGNAA measurements.
- Existing methods still require corrections for variations in body composition.
Purpose of the Study:
- To refine PGNAA accuracy by addressing body habitus and fat layer variations.
- To investigate the utility of Monte Carlo simulations for improving PGNAA analysis.
- To explore methods for reducing the operational costs of PGNAA facilities.
Main Methods:
- Utilized Monte Carlo N-Particle (MCNP) code (version 4A) for detailed analysis of the activation facility.
- Developed correction factors for body habitus and superficial fat layers based on simulation results.
- Investigated the impact of source-to-skin distance on activation uniformity and correction accuracy.
Main Results:
- MCNP simulations enabled more accurate analysis of the PGNAA facility.
- Corrections for body habitus and fat layers were successfully derived.
- Reduced source-to-skin distance maintained correction accuracy despite decreased activation uniformity.
- Lower activity Californium-252 (252Cf) sources can be used, decreasing facility running costs.
Conclusions:
- Monte Carlo simulations significantly enhance the accuracy of PGNAA by providing essential corrections.
- The refined method reduces reliance on patient body habitus, improving measurement reliability.
- Optimized facility design using reduced source activity leads to cost savings.
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