Speaker
Description
Ionizing radiation exposure represents one of the most important health risk for astronauts in space. Radiation dose rates in space are typically more than two orders of magnitude higher than on Earth. Therefore, it is of primordial importance to monitor the astronauts’ radiation doses. However, space dosimetry is very challenging due to the high complexity of the space radiation field consisting of protons, neutrons, electrons and heavy charged particles (HCPs) with energies from few keV up to TeV. Consequently, it is necessary to perform dose mapping experiments inside spacecrafts and to establish individual dose monitoring protocols for astronauts’ radiation protection. Dose mapping and individual dose monitoring in spacecrafts require passive, small, safe and light detectors which are able to measure doses for the whole range of particles and energies. With thermoluminescent (TL) and optically stimulated luminescent (OSL) detectors it is relatively easy to measure the low linear energy transfer (LET) part of the spectrum. The measurement of the high LET part is done typically using track etch detectors, but the dose assessment process with this kind of detectors is very time consuming and requires specialized equipment and personnel. However, it seems that information on the high LET part of the spectrum can be obtained also with more convenient TL and OSL detectors by careful analysis of the TL glow curve’s or OSL decay curve’s shape. The main goal of my PhD is to thoroughly investigate the possibility of determining total radiation doses in space with TL and OSL detectors only. This is being done by combining irradiations of the detectors in space and at different calibrated HCP accelerator facilities with simulations of the space radiation field and its interaction with the spacecraft and the detectors. As a first step of this work, the thermoluminescent proprieties of LiF:Mg,Ti and LiF:Mg,Cu,P detectors exposed to different radiation qualities were investigated and the influence of the dose assessment method on the final results was evaluated. Furthermore, the first detectors coming back from the International Space Station were analyzed as well.
