0554818 - ÚFCH JH 2023 RIV US eng J - Journal Article
Přeček, M. - Kubelík, Petr - Vyšín, L. - Schmidhammer, U. - Larbre, J.-P. - Demarque, A. - Jeunesse, P. - Mostafavi, M. - Juha, L.
Dose Rate Effects in Fluorescence Chemical Dosimeters Exposed to Picosecond Electron Pulses: An Accurate Measurement of Low Doses at High Dose Rates.
Radiation Research. Roč. 197, č. 2 (2022), s. 131-148. ISSN 0033-7587. E-ISSN 1938-5404
R&D Projects: GA ČR GA19-03314S
Grant - others:OP VVV - ADONIS(XE) CZ.02.1.01/0.0/0.0/16_019/0000789
Institutional support: RVO:61388955
Keywords : laser-induced fluorescence * OH radical formation * FBX dosimeter
OECD category: Physical chemistry
Impact factor: 3.4, year: 2022
Method of publishing: Open access

The development of ultra-intense electron pulse for applications needs to be accompanied by the implementation of a practical dosimetry system. In this study four different systems were investigated as dosimeters for low doses with a very high-dose-rate source. First, the effects of ultra-short pulses were investigated for the yields of the Fricke dosimeter based on acidic solutions of ferrous sulfate. It was established that the yields were not significantly affected by the high dose rates, so the Fricke dosimeter system was used as a reference. Then, aqueous solutions of three compounds as fluorescence chemical dosimeters were utilized, each operated at a different solution pH: terephthalic acid basic, trimesic acid acidic, and coumarin-3-carboxylic acid (C3CA) neutral. Fluorescence chemical dosimeters offer an attractive alternative to chemical dosimeters based on optical absorption for measuring biologically relevant low doses because of their higher sensitivity. The effects of very intense dose rate (TGy/ s) from pulses of fast electrons generated by a picosecond linear accelerator on the chemical yields of fluorescence chemical dosimeters were investigated at low peak doses (<20 Gy) and compared with yields determined under low-dose-rate irradiation from a 60 Co gamma-ray source (mGy/s). For the terephthalate and the trimesic acid dosimeters changes in the yields were not detected within the estimated (-10%) precision of the experiments, but, due to the complexity of the mechanism of the hydroxyl radical initiated reactions in solutions of the relevant aromatic compounds, significant reductions of the chemical yield (-60%) were observed when the C3CA dosimeter was irradiated with the ultra-short pulses.
Permanent Link: http://hdl.handle.net/11104/0329461