Development of a Timepix-Based Radiation Monitor for Analyzing Cosmic Radiation on Commercial Aircraft

The Earth is constantly subjected to a diverse field of highly energetic cosmic radiation. At ground level, the atmosphere and magnetosphere provide protection from these damaging rays, but dose rate increases rapidly with altitude. This radiation can pose various biological risks, especially in cases of prolonged exposure. Following the International Commission on Radiological Protection (ICRP)’s 1990 publication classifying aircrew as occupationally exposed workers, a number of studies were implemented to monitor and estimate annual dose received along various flight routes. With the emergence of more advanced radiation detectors, continued measurement and characterization is necessary to verify, expand, and improve upon existing experimental data and computer models. Presented here is a unique approach to measuring the cosmic radiation at commercial aircraft altitudes using a Timepix silicon pixel detector connected to a Raspberry Pi minicomputer. This device is small, portable, easy to operate, and capable of measuring a wide range of radiation field characteristics. The device was successfully tested on four different flights, including three intercontinental and one NASA WB-57 high-altitude. In the data analysis, the measured dose in the silicon sensor is converted to the tissue dose equivalent quantity used for assessing biological risk. Variance in dose rate is compared to altitude and geographical latitude throughout the flight, and total flight doses are compared to predictions made by online codes.