May 15 – 20, 2022
Casino Conference Centre
Europe/Prague timezone

Effects of high dose rates from sub-10-Gy ultrashort electron pulses on the yields of fluorescence chemical dosimeters

May 19, 2022, 2:20 PM
20m
Red Hall

Red Hall

Verbal Radiation Chemistry Radiation Chemistry

Speaker

Dr Martin Precek (ELI Beamlines (FZU CAS))

Description

In the past, the effects of high dose rate of low-LET radiation on the radiation-chemical yields of liquid chemical dosimeters have been systematically studied only for the case of microsecond-length pulses that delivered high peak doses (> 100 Gy). In this study, yields of four different chemical dosimeters were determined at very high dose rates (~1012 Gy/s) but at low peak doses (< 20 Gy) delivered by picosecond electron pulses (ELYSE, Université Paris-Saclay) and were compared with yields determined under low dose rate radiation from a Co-60 gamma ray source (at ~10-3 Gy/s). In addition to the ferrous sulfate (Fricke) dosimeter, three established fluorescence dosimeters were utilized – terephthalic acid, trimesic acid and coumarin-3-carboxylic acid (C3CA). The Fricke dosimeter was used as a reference as it was determined that its chemical yields were not significantly affected by the high dose rates at low doses. The yields of the terephthalate and the trimesic acid dosimeters showed no changes with the elevated dose rate; however, the yield of the coumarin (C3CA) dosimeter suffers a marked drop (-60%). The dissimilar behavior can be explained by differences in the kinetic parameters of the multi-step mechanism of the formation of fluorescent products.

Primary authors

Dr Martin Precek (ELI Beamlines (FZU CAS)) Dr Petr Kubelik (J. Heyrovský Institute of Physical Chemistry of the CAS, v. v. i.) Dr Ludek Vysin (FZU - Institute of Physics of the CAS) Dr Uli Schmidhammer (Institut de Chimie Physique/ELYSE, Université Paris-Saclay) Mr Jean-Philippe Larbre (Institut de Chimie Physique/ELYSE, Université Paris-Saclay) Mr Alexandre Demarque (Institut de Chimie Physique/ELYSE, Université Paris-Saclay) Mr Pierre Jeunesse (Institut de Chimie Physique/ELYSE, Université Paris-Saclay) Prof. Mehran Mostafavi (Institut de Chimie Physique/ELYSE, Université Paris-Saclay) Dr Libor Juha (Institute of Physics & Institute of Plasma Physics of the CAS)

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