Laser illuminated etched track scattering (LITES) dosimetry system

Area of Science:

• Nuclear Science and Engineering
• Radiation Detection and Measurement
• Materials Science

Background:

• Current neutron dosimetry methods at Los Alamos National Laboratory (LANL) using CR-39 etched track foils have limitations.
• The Autoscan 60 system exhibits non-linear responses at higher neutron exposures, restricting its reliable use to below 3 mSv.
• US Department of Energy mandates general employee annual neutron exposure not to exceed 50.0 mSv (5 rem).

Purpose of the Study:

• To develop and evaluate a novel etched track foil reader for neutron dosimetry.
• To assess the linearity and accuracy of the LITES system for neutron dose measurements up to 50 mSv.
• To compare the performance of the LITES system against the established Autoscan 60 system.

Main Methods:

• Development of a Light-Induced Track Etching (LITES) system utilizing a proprietary design.
• Measurement of neutron dose using CR-39 etched track foils exposed to calibrated doses.
• Comparative analysis of dose readings between the LITES prototype and the Autoscan 60 system.

Main Results:

• The LITES system demonstrated a linear response to neutron dose from 0 to 50 mSv with a high correlation coefficient (R² = 0.991).
• The Autoscan 60 system showed good linearity up to approximately 15 mSv but became non-linear at higher exposures (R² = 0.941 from 0 to 50 mSv).
• The LITES system accurately measures neutron doses across the entire range relevant for general employee annual exposure limits.

Conclusions:

• The LITES system offers a significant advancement in neutron dosimetry, providing accurate and linear measurements up to 50 mSv.
• This new technology overcomes the limitations of existing systems, enabling reliable monitoring of higher neutron exposures.
• The LITES system is a viable alternative for meeting regulatory requirements for neutron dose monitoring in occupational settings.