Thermo-electron accumulation in light and heavy water during MHz-burst laser ablation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23640%2F25%3A43975488" target="_blank" >RIV/49777513:23640/25:43975488 - isvavai.cz</a>

Výsledek na webu

<a href="http://hdl.handle.net/11025/59177" target="_blank" >http://hdl.handle.net/11025/59177</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijheatmasstransfer.2024.126573" target="_blank" >10.1016/j.ijheatmasstransfer.2024.126573</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Thermo-electron accumulation in light and heavy water during MHz-burst laser ablation

Popis výsledku v původním jazyce

Laser-induced water ablation triggers various physical effects, including atom ionization, optical breakdown of the liquid, phase explosion, cavitation, and shockwave propagation. These effects may be further amplified in heavy water by deuterium-deuterium fusion reactions, which require extremely high energy levels. Laser pulses can be grouped in bursts to achieve the necessary energy within the ablation plasma plume. This study aims to compare the ablation plasma glow and thermal effects in light and heavy water under both single-pulse and burst-mode ultrashort laser irradiation. Notably, this research introduces the novel application of burst laser ablation in heavy water for the first time. The ablation was conducted beneath the water surface along a circular, laser-scanned trajectory, with two distinct ablation regimes: burst mode and single-pulse mode, utilizing lenses with varying focal lengths and different pulse durations. Absorption processes and plasma glow were monitored using visible and infrared detectors, a fast silicon detector, and a thermocouple. The study revealed that the burst regime in heavy water produced the most intense plasma glow when 1 ps laser pulses were used, with shorter pulses yielding less intense glow and the longest pulses yielding the least. Surprisingly, plasma glow at a lower initial power density of 2.6 &amp; sdot;1013 W/cm2 was four times higher than at a higher power density of 8 &amp; sdot;1013 W/cm2. These findings were compared with existing theories on plasma formation in water by ultrashort laser pulses. The observed increase in pulse-to-pulse plasma glow in burst mode was attributed to thermo-electron accumulation effects. The density of excited and hydrated electrons, and temperature changes of ablated water were calculated using both strong-field ionization and avalanche ionization models. The results of thermocouple measurements were compared with thermal balance calculation. Additionally, the influence of pulse parity on burst ablation glow in heavy water was discussed.

Název v anglickém jazyce

Thermo-electron accumulation in light and heavy water during MHz-burst laser ablation

Popis výsledku anglicky

Laser-induced water ablation triggers various physical effects, including atom ionization, optical breakdown of the liquid, phase explosion, cavitation, and shockwave propagation. These effects may be further amplified in heavy water by deuterium-deuterium fusion reactions, which require extremely high energy levels. Laser pulses can be grouped in bursts to achieve the necessary energy within the ablation plasma plume. This study aims to compare the ablation plasma glow and thermal effects in light and heavy water under both single-pulse and burst-mode ultrashort laser irradiation. Notably, this research introduces the novel application of burst laser ablation in heavy water for the first time. The ablation was conducted beneath the water surface along a circular, laser-scanned trajectory, with two distinct ablation regimes: burst mode and single-pulse mode, utilizing lenses with varying focal lengths and different pulse durations. Absorption processes and plasma glow were monitored using visible and infrared detectors, a fast silicon detector, and a thermocouple. The study revealed that the burst regime in heavy water produced the most intense plasma glow when 1 ps laser pulses were used, with shorter pulses yielding less intense glow and the longest pulses yielding the least. Surprisingly, plasma glow at a lower initial power density of 2.6 &amp; sdot;1013 W/cm2 was four times higher than at a higher power density of 8 &amp; sdot;1013 W/cm2. These findings were compared with existing theories on plasma formation in water by ultrashort laser pulses. The observed increase in pulse-to-pulse plasma glow in burst mode was attributed to thermo-electron accumulation effects. The density of excited and hydrated electrons, and temperature changes of ablated water were calculated using both strong-field ionization and avalanche ionization models. The results of thermocouple measurements were compared with thermal balance calculation. Additionally, the influence of pulse parity on burst ablation glow in heavy water was discussed.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/EH22_008%2F0004634" target="_blank" >EH22_008/0004634: Strojní inženýrství biologických a bioinspirovaných systémů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

ISSN

0017-9310

e-ISSN

1879-2189

Svazek periodika

239

Číslo periodika v rámci svazku

APR 2025

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

nestránkováno

Kód UT WoS článku

001389685600001

EID výsledku v databázi Scopus

2-s2.0-85211996602