Measurement of the concetration of the OH radical in an
atmospheric pressure plasma pencil by laser-induced
fluorescence

a 2013

Measurement of the concetration of the OH radical in an atmospheric pressure plasma pencil by laser-induced fluorescence

VORÁČ, Jan, Pavel DVOŘÁK and Vojtěch PROCHÁZKA

Basic information

Original name

Measurement of the concetration of the OH radical in an atmospheric pressure plasma pencil by laser-induced fluorescence

Authors

VORÁČ, Jan (203 Czech Republic, guarantor, belonging to the institution), Pavel DVOŘÁK (203 Czech Republic, belonging to the institution) and Vojtěch PROCHÁZKA (203 Czech Republic, belonging to the institution)

Edition

5th CESPC, 2013

Other information

Language

English

Type of outcome

Konferenční abstrakt

Field of Study

10305 Fluids and plasma physics

Country of publisher

Hungary

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14310/13:00069449

Organization unit

Faculty of Science

ISBN

978-615-5270-04-8

Keywords in English

planar; laser-induced fluorescence; hydroxyl; spatially resolved; argon; atmsopheric pressure; plasma jet

Změněno: 25/9/2013 12:22, Mgr. Jan Voráč, Ph.D.

Abstract

V originále

The concentration of radicals in reactive plasmas is an important parameter. The hydroxyl (OH) radical is known to be a strongly oxidizing species as well as an efficient source of UV radiation. Measuring the concentration of diatomic radicals at atmospheric pressure is a non-trivial task, especially in plasmas of small volume, such as the plasma pencil. One of the few methods suitable for this task is the laser-induced fluorescence, however, the interpretation of results at high pressures is difficult. We present a scheme suitable for measuring the concentration of the OH concentration in the flow of a rare gas mixing weakly with the ambient atmosphere. By exciting the ground vibrational state (v'=0) of the first excited electronic state (A2Sigma) we avoid the vibrational energy transfer (VET) in the laser-excited state. Together with the verified fact that the rotational energy transfer (RET) in the excited vibronic state is very fast, this justified using the very simple two-level model with (A2Sigma, v'=0) and (X2Pi,v''=0) vibronic states assumed to be in thermal rotational equilibrium during the whole process. The electronic quenching is taken into account by directly measuring the lifetime of the laser-excited state. The calibration is done by the Rayleigh scattering on air.

Links

CZ.1.05/2.1.00/03.0086, interní kód MU

Name: CEPLANT - Regionální VaV centrum pro nízkonákladové plazmové a nanotechnologické povrchové úpravy

Investor: Ministry of Education, Youth and Sports of the CR, 2.1 Regional R&D Centres

ED2.1.00/03.0086, research and development project

Name: Regionální VaV centrum pro nízkonákladové plazmové a nanotechnologické povrchové úpravy

Citovat

VORÁČ, Jan, Pavel DVOŘÁK and Vojtěch PROCHÁZKA. Measurement of the concetration of the OH radical in an atmospheric pressure plasma pencil by laser-induced fluorescence. In 5th CESPC. 2013. ISBN 978-615-5270-04-8.

@proceedings{1123170,
   author = {Voráč, Jan and Dvořák, Pavel and Procházka, Vojtěch},
   booktitle = {5th CESPC},
   keywords = {planar; laser-induced fluorescence; hydroxyl; spatially resolved; argon; atmsopheric pressure; plasma jet},
   language = {eng},
   isbn = {978-615-5270-04-8},
   title = {Measurement of the concetration of the OH radical in an atmospheric pressure plasma pencil by laser-induced fluorescence},
   year = {2013}
}

TY  - CONF
ID  - 1123170
AU  - Voráč, Jan - Dvořák, Pavel - Procházka, Vojtěch
PY  - 2013
TI  - Measurement of the concetration of the OH radical in an atmospheric pressure plasma pencil by laser-induced fluorescence
SN  - 9786155270048
KW  - planar
KW  - laser-induced fluorescence
KW  - hydroxyl
KW  - spatially resolved
KW  - argon
KW  - atmsopheric pressure
KW  - plasma jet
N2  - The concentration of radicals in reactive plasmas is an important parameter. The hydroxyl (OH) radical is known to be a strongly oxidizing species as well as an efficient source of UV radiation. Measuring the concentration of diatomic radicals at atmospheric pressure is a non-trivial task, especially in plasmas of small volume, such as the plasma pencil. One of the few methods suitable for this task is the laser-induced fluorescence, however, the interpretation of results at high pressures is difficult. We present a scheme suitable for measuring the concentration of the OH concentration in the flow of a rare gas mixing weakly with the ambient atmosphere. By exciting the ground vibrational state (v'=0) of the first excited electronic state (A2Sigma) we avoid the vibrational energy transfer (VET) in the laser-excited state. Together with the verified fact that the rotational energy transfer (RET) in the excited vibronic state is very fast, this justified using the very simple two-level model with (A2Sigma, v'=0) and (X2Pi,v''=0) vibronic states assumed to be in thermal rotational equilibrium during the whole process. The electronic quenching is taken into account by directly measuring the lifetime of the laser-excited state. The calibration is done by the Rayleigh scattering on air.
ER  -

VORÁČ, Jan, Pavel DVOŘÁK and Vojtěch PROCHÁZKA. Measurement of the concetration of the OH radical in an atmospheric pressure plasma pencil by laser-induced fluorescence. In \textit{5th CESPC}. 2013. ISBN~978-615-5270-04-8.

Detailed Information on Publication Record