Critical Review of Water Radiolysis Processes, Dissociation Products, and Possible Impacts on the Local Environment: A Geochemist

2013 ◽  
Vol 66 (5) ◽  
pp. 522 ◽  
Author(s):  
Soumya Das
Keyword(s):  
Energy Transfer ◽  
Molecular Species ◽  
Critical Review ◽  
Vapour Pressure ◽  
Linear Energy Transfer ◽  
Local Environment ◽  
Metal Mobility ◽  
Water Radiolysis ◽  
Reactive Radicals ◽  
Hydroxide Radicals

Radiolysis of water is the process whereby water dissociates due to various types of ionizing radiation (α, β, and γ) into hydrogen and hydroxide radicals (instead of hydrogen and hydroxide ions as in ionization). During radiolysis, water breaks down to highly reactive radicals such as •OH, •H, eaq–, HO2, and O2–• and molecular species such as H2, O2, and H2O2. Yields of these dissociation products are largely dependent on factors including the type of radiation, vapour pressure of the system, and linear energy transfer. These dissociated radicals are highly reactive and can affect the local environment by changing redox conditions and, in turn, inducing and enhancing metal mobility in the environment. This article reviews the process of water radiolysis, dissociation products, and possible effects on the environment.

Yields of primary species in the low-linear energy transfer radiolysis of water in the temperature range of 25–700 °C

2020 ◽  
Vol 22 (14) ◽  
pp. 7430-7439
Author(s):  
Abida Sultana ◽  
Jintana Meesungnoen ◽  
Jean-Paul Jay-Gerin
Keyword(s):  
Monte Carlo ◽  
Energy Transfer ◽  
Linear Energy Transfer ◽  
Water Radiolysis ◽  
Temperature Range

Monte Carlo track chemistry simulations were used to calculate the yields (G values) for the radical (eaq−, H˙, ˙OH) and molecular (H2, H2O2) species formed in low-LET water radiolysis from ∼1 ps to 1 ms between 25 and 700 °C, at 25 MPa pressure.

Monte-Carlo calculation of the primary yields of H2O2 in the 1H+, 2H+, 4He2+, 7Li3+, and 12C6+ radiolysis of liquid water at 25 and 300°C

2002 ◽  
Vol 80 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Jintana Meesungnoen ◽  
Jean-Paul Jay-Gerin ◽  
Abdelali Filali-Mouhim ◽  
Samlee Mankhetkorn
Keyword(s):  
Hydrogen Peroxide ◽  
Monte Carlo ◽  
Energy Transfer ◽  
Monte Carlo Simulations ◽  
Liquid Water ◽  
Linear Energy Transfer ◽  
Average Distance ◽  
Water Radiolysis ◽  
Model Calculations ◽  
Primary Yield

Monte-Carlo simulations are used to calculate the primary yield of hydrogen peroxide (GH2O2) of the radiolysis of pure, deaerated liquid water as a function of linear energy transfer (LET) of the incident radiation over the range ~0.3–100 keV µm–1, at 25 and 300°C. The radiations include 1H+, 2H+, 4He2+, 7Li3+, and 12C6+ ions with energies from 0.17 MeV to 3.6 GeV. At 25°C, it is found that our GH2O2 values, calculated with protons of different initial energies, show a monotonic increase as a function of LET, in agreement with the commonly assumed expectation of an increase in molecular yields with increasing LET. Our calculated H2O2 yields at 300°C increase significantly faster with LET than do their corresponding 25°C values, showing that the temperature dependence of GH2O2 at higher LET is less than for low-LET radiation. We also report our results on the temporal variations of the H2O2 yields, in the interval ~1 × 10–13 – 1 × 10–6 s, at 25 and 300°C and for the different types of radiation considered. Finally, we find that for incident ions of equal LET > 10 keV µm–1, GH2O2 decreases as the ion velocity increases, from protons (or deuterons) to carbon ions. These differences produced in GH2O2 by changing the type of radiation are explained by the greater mean energy of secondary electrons from the higher velocity ions, which penetrate to a greater average distance from the actual particle track, with a corresponding decrease in molecular yields. Our calculated GH2O2 values compare generally well with the experimental data available from the literature and are also in good accord with the predictions of deterministic diffusion-kinetic model calculations reported earlier.Key words: liquid water, radiolysis, primary yields, hydrogen peroxide (H2O2), linear energy transfer (LET), accelerated protons and heavy ions, temperature, Monte-Carlo simulations.

Monte Carlo simulation study of the effects of acidity and LET on the primary free-radical and molecular yields of water radiolysis — Application to the Fricke dosimeter

2007 ◽  
Vol 85 (3) ◽  
pp. 214-229 ◽  
Author(s):  
Narongchai Autsavapromporn ◽  
Jintana Meesungnoen ◽  
Ianik Plante ◽  
Jean-Paul Jay-Gerin
Keyword(s):  
Monte Carlo ◽  
Energy Transfer ◽  
Free Radicals ◽  
Sulfuric Acid ◽  
Free Radical ◽  
Monte Carlo Simulations ◽  
Linear Energy Transfer ◽  
Oh Radicals ◽  
Water Radiolysis ◽  
Monte Carlo Simulation Study

Monte Carlo simulations are used to investigate the effects of acidity (pH) on the primary yields of various chemical species produced in the radiolysis of de-aerated aqueous sulfuric acid solutions over the range from neutral solution to 0.4 mol/L H2SO4. The effects of the quality of radiation, measured in terms of linear energy transfer (LET), have also been studied for LET varying from ~0.3 to 15 keV/µm at ambient temperature. Our results show that an increase in acidity (1 < pH < 4) leads to an increase in the yield [Formula: see text] of the "reducing" free radicals (hydrated electron and H• atom) and a slight increase in G·OH and [Formula: see text], while there is a slight decrease in [Formula: see text] At pH < 1, •OH radicals react with HSO4- anions to form SO4·– radicals, resulting in a steep decrease in G.OH. By contrast, in the range of pH from ~4 to 7, the calculated yield values are independent of sulfuric acid concentration. In both neutral water and 0.4 mol/L H2SO4 (pH 0.46) solutions, the primary molecular yields increase upon increasing LET to ~15 keV/µm with a concomitant decrease in those of free radicals. As an exception, GH. at first increases with LET, reaching a maximum near 6.5 keV/µm before decreasing steeply at higher LET. The results obtained are generally in good agreement with available experimental data over the whole acidity and LET ranges studied. Finally, as an application, we have simulated the radiation-induced oxidation of ferrous sulfate solutions in aerated aq. 0.4 mol/L H2SO4 (Fricke dosimeter) as a function of time up to ~50 s and addressed the effects of LET on the resulting ferric ion yield at 25 °C. The production of Fe3+ ions is highly sensitive to free-radical yields, especially H• atoms (via formation of HO2•), resulting in a marked decline of G(Fe3+) with increasing LET. The general trend of the observed variation of G(Fe3+) with radiation quality is well reproduced by our computed Fe3+ ion yield values.Key words: liquid water, acidic (H2SO4) aqueous solutions, radiolysis, free-radical and molecular yields, linear energy transfer (LET), Fricke dosimeter, Monte Carlo simulations.

Unresectable Chondrosarcomas Treated With Carbon Ion Radiotherapy: Relationship Between Dose-averaged Linear Energy Transfer and Local Recurrence

2020 ◽  
Vol 40 (11) ◽  
pp. 6429-6435
Author(s):  
SHINNOSUKE MATSUMOTO ◽  
SUNG HYUN LEE ◽  
REIKO IMAI ◽  
TAKU INANIWA ◽  
NARUHIRO MATSUFUJI ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Local Recurrence ◽  
Linear Energy Transfer ◽  
Carbon Ion Radiotherapy ◽  
Carbon Ion

Low-linear energy transfer radiolysis of liquid water at elevated temperatures up to 350°C: Monte-Carlo simulations

2011 ◽  
Vol 508 (4-6) ◽  
pp. 224-230 ◽  
Author(s):  
S. Sanguanmith ◽  
Y. Muroya ◽  
J. Meesungnoen ◽  
M. Lin ◽  
Y. Katsumura ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Energy Transfer ◽  
Monte Carlo Simulations ◽  
Liquid Water ◽  
Linear Energy Transfer ◽  
Elevated Temperatures

scholarly journals Influence of dose-averaged linear energy transfer on tumour control after carbon-ion radiation therapy for pancreatic cancer

2020 ◽  
Vol 21 ◽  
pp. 19-24 ◽  
Author(s):  
Yasuhito Hagiwara ◽  
Tapesh Bhattacharyya ◽  
Naruhiro Matsufuji ◽  
Yuka Isozaki ◽  
Hirotoshi Takiyama ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Radiation Therapy ◽  
Energy Transfer ◽  
Linear Energy Transfer ◽  
Carbon Ion ◽  
Tumour Control

The cytotoxicity of high-linear energy transfer radiation is reinforced by oxaliplatin in human glioblastoma cells

2007 ◽  
Vol 254 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Sami Benzina ◽  
Frederic Debomy ◽  
Jean-Pierre Bergerat ◽  
Jean-Marc Denis ◽  
John Gueulette ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Linear Energy Transfer ◽  
Glioblastoma Cells ◽  
Human Glioblastoma ◽  
Human Glioblastoma Cells ◽  
Linear Energy Transfer Radiation ◽  
High Linear Energy Transfer
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