Record |
Author |
Kelly, S.; van de Steeg, A.; Hughes, A.; van Rooij, G.; Bogaerts, A. |
Title |
Thermal instability and volume contraction in a pulsed microwave N2plasma at sub-atmospheric pressure |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Plasma Sources Science & Technology |
Abbreviated Journal |
Plasma Sources Sci T |
Volume |
30 |
Issue |
5 |
Pages |
055005 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We studied the evolution of an isolated pulsed plasma in a vortex flow stabilised microwave (MW) discharge in N2 at 25 mbar via the combination of 0D kinetics modelling, iCCD imaging and laser scattering diagnostics. Quenching of electronically excited N2 results in fast gas heating and the onset of a thermal-ionisation instability, contracting the discharge volume. The onset of a thermal-ionisation instability driven by vibrational excitation pathways is found to facilitate significantly higher N2 conversion (i.e. dissociation to atomic N2 ) compared to pre-instability conditions, emphasizing the potential utility of this dynamic in future fixation applications. The instability onset is found to be instigated by super-elastic heating of the electron energy distribution tail via vibrationally excited N2 . Radial contraction of the discharge to the skin depth is found to occur post instability, while the axial elongation is found to be temporarily contracted during the thermal instability onset. An increase in power reflection during the thermal instability onset eventually limits the destabilising effects of exothermic electronically excited N2 quenching. Translational and vibrational temperature reach a quasi-non-equilibrium after the discharge contraction, with translational temperatures reaching ∼1200 K at the pulse end, while vibrational temperatures are found in near equilibrium with the electron energy (1 eV, or ∼11 600 K). This first description of the importance of electronically excited N2 quenching in thermal instabilities gives an additional fundamental understanding of N2 plasma behaviour in pulsed MW context, and thereby brings the eventual implementation of this novel N2 fixation method one step closer. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000648710900001 |
Publication Date |
2021-05-01 |
Series Editor ![sorted by Series Editor field, ascending order (up)](img/sort_asc.gif) |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0963-0252 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.302 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
Stichting voor de Technische Wetenschappen, 733.000.002 ; Fonds Wetenschappelijk Onderzoek, 30505023 GoF9618n ; H2020 European Research Council, 810182 ; H2020 Marie Skłodowska-Curie Actions, 813393 838181 ; SK & AB acknowledge financial support by the European Marie Skłodowska-Curie Individual Fellowship ‘PENFIX’ within Horizon 2020 (Grant No. 838181), the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 810182—SCOPE ERC Synergy project), and the Excellence of Science FWO-FNRS project (FWO Grant ID GoF9618n, EOS ID 30505023). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Centre VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. SK and AB would like to thank Mr Luc van ’t dack, Dr Karen Leyssens and Ing. Karel Venken for their technical assistance. AvdS, AH and GvR are grateful to Ampleon for the use of their solid-state microwave amplifier units and acknowledge financial support from the Netherlands Organisation for Scientific Research (NWO Grant No. 733.000.002) in the framework of the CO2 -to-products programme with kind support from Shell, and the ENW PPP Fund for the top sectors. This project has been partially funded by the European Union’s Horizon 2020 research and innovation programme ‘Pioneer’ under the Marie Skłodowska-Curie Grant Agreement No. 813393. |
Approved |
Most recent IF: 3.302 |
Call Number |
PLASMANT @ plasmant @c:irua:178122 |
Serial |
6759 |
Permanent link to this record |