Dose assessment of aircrew using passive detectors

Area of Science:

• Radiation protection
• Aviation dosimetry
• Cosmic ray physics

Background:

• Aircrew radiation exposure is a critical concern, emphasized by European Council directive 96/29/Euratom.
• Cosmic ray-induced neutrons constitute over 50% of the biologically relevant dose at flight altitudes.
• Current dose assessment relies on computational methods (e.g., CARI) and extensive experimental setups.

Purpose of the Study:

• To evaluate thermoluminescence dosemeters (TLDs) as a practical alternative for aircrew radiation exposure monitoring.
• To assess the effectiveness of the high-temperature ratio method with LiF:Mg,Ti TLDs for dose equivalent determination.
• To present ongoing measurements using CaF2:Tm TLDs for aircrew dosimetry.

Main Methods:

• Utilized LiF:Mg,Ti thermoluminescence dosemeters onboard aircraft.
• Applied the high-temperature ratio method to determine averaged linear energy transfer (LET).
• Compared TLD measurements with computational dose assessment models and experimental data.

Main Results:

• Demonstrated the capability of LiF:Mg,Ti TLDs and the high-temperature ratio method to estimate dose equivalent based on ICRP's Q(LETinfinity) relationship.
• Highlighted the suitability of TLDs due to their small size and ease of handling for in-flight measurements.
• Presented preliminary results from ongoing measurements with CaF2:Tm dosemeters.

Conclusions:

• Thermoluminescence dosimetry, particularly using LiF:Mg,Ti, provides a viable and practical approach for monitoring aircrew radiation exposure.
• The high-temperature ratio method effectively estimates biologically relevant doses in mixed radiation fields encountered during aviation.
• CaF2:Tm TLDs are under investigation for further advancements in aircrew dosimetry.