Iron salts in solid state and in frozen solutions as dosimeters for low irradiation temperatures

The aim of this work is to study the irradiation of iron salts in solid state (heptahydrated ferrous sulfate) and in frozen acid solutions. The study is focused on finding their possible use as dosimeters for low temperature irradiations and high doses. The analysis of the samples was made by UV-visible and Mössbauer spectroscopies. The output signal was linear from 0 to 10 MGy for the solid samples, and 0-600 Gy for the frozen solutions. The obtained data is reproducible and easy to handle. For these reasons, heptahydrate iron sulfate is a suitable dosimeter for low temperature and high irradiation doses, in solid state, and in frozen solution.

Dependence of irradiation temperature in the response of iron salts

A potential dosimeter based on aqueous frozen solutions and solid-state salt are presented for the evaluation of the energy transferred during the interaction of high-energy radiation with matter at low temperature. The foundation of these dosimeters, both the solid state and the frozen solutions, is based on the measurement of the change of the iron oxidation state. The systems were irradiated with gamma radiation at different doses (up to 10 MGy), and at different temperatures (from 77 to 298 K). The irradiated samples were analysed by UV-spectroscopy and Mössbauer spectroscopy. A theoretical model was developed for the chemical reactions system. This model reproduces the experimental effects produced by the irradiation in aqueous solutions of ferrous salt. The results showed that the response of the dosimeters depends on the irradiation temperature. At low-radiation doses, the response was linear. In particular, this work can be applied to low-temperature dosimetry can be specially applied to simulation experiments of extraterrestrial bodies, as well as in general to space research.