Speaker
Description
Cosmic radiation at commercial flight altitudes represents a mixed high-energy field whose spectral composition and particle balance vary with geomagnetic latitude, altitude, and solar modulation. These variations influence detector response and introduce systematic uncertainties into routinely reported operational quantities such as ambient dose equivalent 𝐻∗(10).
This study examines how radiation field characteristics encountered along a dedicated research flight affect the uncertainty and stability of onboard dosimetric quantities. Emphasis is placed on comparison between 𝐻∗(10) and absorbed dose in silicon 𝐷𝑆𝑖, assessed using in-flight measurements with active detectors including semiconductor spectrometers (Liulin, AIRDOS) and a reference TEPC instrument (Hawk).
TEPC-based systems provide a well-established reference for 𝐻∗(10), their operational deployment is limited by size, power requirements, and supervised operation, restricting their suitability for long-term autonomous aircraft monitoring. Semiconductor detectors calibrated to 𝐻∗(10) in high-energy reference fields such as CERF provide practical alternatives. However, calibration coefficients are valid only for the spectral conditions of the reference field. As neutron and low-LET contributions change with geographic position and atmospheric conditions, systematic deviations from reference 𝐻∗(10) values may arise.
Absorbed dose in silicon 𝐷𝑆𝑖 represents a directly measured physical quantity corresponding to deposited energy in the detector material. Unlike 𝐻∗(10), it does not rely on spectral conversion coefficients that amplify neutron contributions through large weighting factors. Consequently, 𝐷𝑆𝑖 demonstrates improved robustness against radiation field variability and reduced model dependence.
Model calculations using CARI-7 and other codes evaluate spectral changes along flight trajectories and compare predicted and measured quantities.
The results indicate that radiation field variability constitutes a significant source of systematic uncertainty for 𝐻∗(10) when derived from semiconductor detectors calibrated under fixed reference conditions. For validation and verification of transport codes and construction of long-term aviation radiation databases, absorbed dose in silicon emerges as the more stable and traceable primary quantity.