Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer
(1) Background: Water radiolysis leads to the formation of hydronium ions H<sub>3</sub>O<sup>+</sup> in less than 50 fs, resulting in the formation of transient acidic pH spikes in the irradiated water. The purpose of this study is to examine the time evolution of these spike...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-09-01
|
| Series: | Radiation |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2673-592X/3/3/14 |
| _version_ | 1797577413727617024 |
|---|---|
| author | Md Ibrahim Bepari Jintana Meesungnoen Jean-Paul Jay-Gerin |
| author_facet | Md Ibrahim Bepari Jintana Meesungnoen Jean-Paul Jay-Gerin |
| author_sort | Md Ibrahim Bepari |
| collection | DOAJ |
| description | (1) Background: Water radiolysis leads to the formation of hydronium ions H<sub>3</sub>O<sup>+</sup> in less than 50 fs, resulting in the formation of transient acidic pH spikes in the irradiated water. The purpose of this study is to examine the time evolution of these spikes of acidity under irradiation conditions combining both high absorbed dose rate and high-LET radiation. (2) Methods: The early space–time history of the distributions of the various reactive species was obtained using our Monte Carlo multitrack chemistry simulation code IONLYS-IRT. To simulate different LETs, we used incident protons of varying energies as radiation sources. The “instantaneous pulse” (or Dirac) model was used to investigate the effect of dose rate. (3) Results: One major finding is that the combination of high dose rates and high LETs is clearly additive, with a very significant impact on the pH of the solution. For example, at 1 ns and for a dose rate of ~10<sup>7</sup> Gy/s, the pH drops from ~4.7 to 2.7 as the LET increases from ~0.3 to 60 keV/μm. (4) Conclusions: Confirming previous work, this purely radiation chemical study raises the question of the possible importance and role of these spikes of acidity in underpinning the physical chemistry and biology of the “FLASH effect”. |
| first_indexed | 2024-03-10T22:07:57Z |
| format | Article |
| id | doaj.art-f2426c9486da4fc59251e576c7994175 |
| institution | Directory Open Access Journal |
| issn | 2673-592X |
| language | English |
| last_indexed | 2024-03-10T22:07:57Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Radiation |
| spelling | doaj.art-f2426c9486da4fc59251e576c79941752023-11-19T12:44:30ZengMDPI AGRadiation2673-592X2023-09-013316518210.3390/radiation3030014Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy TransferMd Ibrahim Bepari0Jintana Meesungnoen1Jean-Paul Jay-Gerin2Département de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12ème Avenue Nord, Sherbrooke, QC J1H 5N4, CanadaDépartement de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12ème Avenue Nord, Sherbrooke, QC J1H 5N4, CanadaDépartement de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12ème Avenue Nord, Sherbrooke, QC J1H 5N4, Canada(1) Background: Water radiolysis leads to the formation of hydronium ions H<sub>3</sub>O<sup>+</sup> in less than 50 fs, resulting in the formation of transient acidic pH spikes in the irradiated water. The purpose of this study is to examine the time evolution of these spikes of acidity under irradiation conditions combining both high absorbed dose rate and high-LET radiation. (2) Methods: The early space–time history of the distributions of the various reactive species was obtained using our Monte Carlo multitrack chemistry simulation code IONLYS-IRT. To simulate different LETs, we used incident protons of varying energies as radiation sources. The “instantaneous pulse” (or Dirac) model was used to investigate the effect of dose rate. (3) Results: One major finding is that the combination of high dose rates and high LETs is clearly additive, with a very significant impact on the pH of the solution. For example, at 1 ns and for a dose rate of ~10<sup>7</sup> Gy/s, the pH drops from ~4.7 to 2.7 as the LET increases from ~0.3 to 60 keV/μm. (4) Conclusions: Confirming previous work, this purely radiation chemical study raises the question of the possible importance and role of these spikes of acidity in underpinning the physical chemistry and biology of the “FLASH effect”.https://www.mdpi.com/2673-592X/3/3/14water radiolysisradiation dose ratelinear energy transfer (LET)acidity (pH)Monte Carlo multitrack chemistry simulationradiation chemical yield (<i>G</i> value) |
| spellingShingle | Md Ibrahim Bepari Jintana Meesungnoen Jean-Paul Jay-Gerin Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer Radiation water radiolysis radiation dose rate linear energy transfer (LET) acidity (pH) Monte Carlo multitrack chemistry simulation radiation chemical yield (<i>G</i> value) |
| title | Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer |
| title_full | Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer |
| title_fullStr | Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer |
| title_full_unstemmed | Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer |
| title_short | Early and Transient Formation of Highly Acidic pH Spikes in Water Radiolysis under the Combined Effect of High Dose Rate and High Linear Energy Transfer |
| title_sort | early and transient formation of highly acidic ph spikes in water radiolysis under the combined effect of high dose rate and high linear energy transfer |
| topic | water radiolysis radiation dose rate linear energy transfer (LET) acidity (pH) Monte Carlo multitrack chemistry simulation radiation chemical yield (<i>G</i> value) |
| url | https://www.mdpi.com/2673-592X/3/3/14 |
| work_keys_str_mv | AT mdibrahimbepari earlyandtransientformationofhighlyacidicphspikesinwaterradiolysisunderthecombinedeffectofhighdoserateandhighlinearenergytransfer AT jintanameesungnoen earlyandtransientformationofhighlyacidicphspikesinwaterradiolysisunderthecombinedeffectofhighdoserateandhighlinearenergytransfer AT jeanpauljaygerin earlyandtransientformationofhighlyacidicphspikesinwaterradiolysisunderthecombinedeffectofhighdoserateandhighlinearenergytransfer |