Investigation of the initial phases of nanosecond discharges in liquid water

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F20%3A00531307" target="_blank" >RIV/61389021:_____/20:00531307 - isvavai.cz</a>

Alternative codes found

RIV/00216224:14310/20:00114468

Result on the web

<a href="https://iopscience.iop.org/article/10.1088/1361-6595/ab87b7" target="_blank" >https://iopscience.iop.org/article/10.1088/1361-6595/ab87b7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-6595/ab87b7" target="_blank" >10.1088/1361-6595/ab87b7</a>

Result language

angličtina

Original language name

Investigation of the initial phases of nanosecond discharges in liquid water

Original language description

In this work, we examine initial phases of micro-discharges produced in deionised water by high-voltage (HV) pulses of nanosecond duration. We apply opto-electrical diagnostics with extremely high temporal (down to 30 ps) as well as spatial (down to 1 μm) resolution. Frozen interferometric and shadowgraph images show three distinct events. The first, the subcritical (no-discharge) event, is characterised by periodic perturbations of the index of refraction which depart from the anode surface and are pulled away at the speed of sound as an expanding envelope defined by the shape of the anode tip. One-dimensional hydrodynamic modelling of the subcritical phase under conditions mimicking curvatures of real anode tips reveals basic characteristics of perturbations caused by dynamic balance between the hydrostatic and electrostrictive pressures consistent with experimental observations. The second, the dark or non-luminous discharge event, is characterised by the onset of a few isolated very tiny tree-like structures growing from the anode tip. Depending on the HV amplitude, the initial structures occur with a delay of ∼2-3 ns after onset of the HV pulse and subsequently expand with average velocity of ∼1 ± 105-2 ± 105 m s-1, creating very dense bush-like structures made of thin hair-like filaments in a few nanoseconds. The third, the luminous discharge event, follows (nearly simultaneously) the dark discharge event and unveils much simpler tree-like morphology determined by the extension of non-luminous bush-like structures. Characteristic dimensions of observed events range from about 1 μm (typical diameter of non-luminous filaments) to tens of micrometres (characteristic diameters of luminous filaments). Furthermore, we address a possible role of microbubbles developing in the anode region due to the periodic HV pulses and verify that the UV-vis-NIR spectrometric signatures of the luminous phase notably change when replacing non-degassed deionised water with degassed.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

<a href="/en/project/GA18-04676S" target="_blank" >GA18-04676S: Fundamental phenomena of nanosecond discharge in liquid water</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

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

Name of the periodical

Plasma Sources Science & Technology

ISSN

0963-0252

e-ISSN

—

Volume of the periodical

29

Issue of the periodical within the volume

6

Country of publishing house

GB - UNITED KINGDOM

Number of pages

17

Pages from-to

064001

UT code for WoS article

000575399800001

EID of the result in the Scopus database

2-s2.0-85087106326