INVESTIGATION ON THE USE OF FRICKE DOSIMETRY FOR COSMIC RADIATION

Abstract

The dosimetry of cosmic radiation outside Earth's atmosphere is a significant challenge due to the high complexity of radiation fields encountered in Low Earth Orbit (LEO) and interplanetary space, in addition to the constraints imposed by instrument spaceflight. The Fricke dosimeter is a water-based (96% by mass) chemical dosimetry system that offers the potential to measure the absorbed dose in water in an arbitrary geometry, for doses of up to 400 Gy, for different energy spectra. The LCR/UERJ was part of the Cubes in Space project. The main goal of this work was to obtain absorbed doses in water at different altitudes in the atmosphere using rocket and balloon systems sent by NASA's space station, using the Fricke dosimeter. For each project, 10 polyethylene bags with the Fricke dosimeter were made. The dosimeters were sent on a 20-cubic-meter helium balloon to a target altitude of at least 36.5 km, where they experienced conditions close to space. The average dose in the Fricke solution in the balloon was 9.3 ± 1.5 Gy and in the rocket was 20.4 ± 1.4 Gy. The maximum altitude reached by the balloon is 36.5 km, with a flight duration of approximately 12 hours. On the other hand, the rocket reaches a maximum altitude of 120 km, but it remains in flight for only a few minutes. The 54% difference in the absorbed dose can be explained by the different particles that are responsible for the cosmic radiation in different altitudes. Cosmic radiation increases with altitude in the atmosphere and can vary from hour to hour. The Fricke dosimeter has proven to be effective for aerospace dosimetry, as it was utilized according to the presented boundary conditions. Gathering more technical flight information can lead to future results with greater precision and lower uncertainties.