HAL Id: jpa-00249702
https://hal.archives-ouvertes.fr/jpa-00249702
Submitted on 1 Jan 1997
HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Vacuum Ultraviolet Absorption of S2OF10
A. Casanovas, I. Coll, C. Pradayrol, J. Guelfucci, J. Casanovas
To cite this version:
A. Casanovas, I. Coll, C. Pradayrol, J. Guelfucci, J. Casanovas. Vacuum Ultraviolet Absorption of S2OF10. Journal de Physique III, EDP Sciences, 1997, 7 (11), pp.2103-2105. �10.1051/jp3:1997243�.
�jpa-00249702�
J. Phys III lifance 7 (1997) 2103-2105 NOVEMBER1997, PAGE 2103
Short Communication
Vacuum Ultraviolet Absorption of S20Fio
A-M- Casanovas (~i*), I. Coll (~)~ C. Pradayrol (~), J-P- Guelfucci (~) and J. Casanovas (~)
(~) Laboratoire de Biophysique et de Biomath4matiques, Facult6 de Pharmacie, Universitd Paul Sabatier, 35 chemin des &~araichers, 31062 Toulouse Cedex 4, France (~) Centre de Physique des Plasmas et de leurs Applications de Toulouse, ESA 5002,
Universitd Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex 4, France
(Received 14 April 1997, revised 9 September J997, accepted J6 September 1997)
PACS.52.80 Mg Arcsj sparks; lightning
Abstract. Absorption coefficients ko (m~~ 100 kPa~~ of S20Fio.
a gaseous by-product of electrically stressed SF6~ were measured between 122 and 202 nm The experiments were carried out at a temperature of 298 K and a spectral resolution of 01 nm over the whole wavelength
range The results complete those we previously published on SF6, SF4~ SOF2 and S02F2 absorption m the same wavelength region iii.
Rdsumd. Les coefficients d'absorption ko (m~~ loo kPa~~ du S20Fio qui constitue l~un des
produits de dAcomposition gazeux du SF6 soumis h des contraintes dlectriques ont Atd mesur4s
entre 122 et 202 nm Les expAriences ont AtA rAalisAes h la tempArature de 298 K avec une
rAsolution de o-I nm sur toute la gamme de longueurs d~onde. Ces rAsultats complAtent ceux
que nous avons prAcAdemment publiAs sur l'absorption du SF6, du SF4, du SOF2 et du S02F2
dans le mAme domaine de longueurs d'onde Iii.
We recently published absorption coefficients of sulfur hexafluoride (SF6), which constitutes the most widely used insulating gas in high voltage apparatuses, and of its main gaseous by-
products under coronas, sparks or arcs: sulfur tetrafluoride (SF4), thionyl fluoride (SOF2) and
sulfuryl fluoride (S02F2), in the wavelength range 115-200 nm iii.
The knowledge of these absorption spectra is essential for instance for arc modeling stud- ies. Indeed, as in power arcs or sparks radiative transfer constitutes a particularly important mechanism. the absorption by the surrounding cold gas of the radiation emitted by the plasma
results in an heating of this gas and therefore to a pressure increase u-hich may have a strong influence on the circuit-breaker behaviour.
In addition to SF4, SOF2 and S02F2 other gaseous compounds are formed m much smaller
quantities n>hen SF6 is subjected to electrical discharges, this is the case, for example, of disulfur decafluoride (S2Fio), Pentafluorosulfur oxide (S20Fio), bis(pentafluoro-sulfur)peroxide (S202Fio) and S203F6 (2-6].
(*) Author for correspondence
@ Les flditions de Physique 1997
2104 JOURNAL DE PHYSIQUE III N°11
105 ,
a +
a +
1o4 * & +~
'~
+~§
103
'~
$ C
~ ~hG ~~
~
r 102
~ ~ +
. +
~ $ B~%w~~ A
w° 10~ ~ n~
. ~n
10° ',
.
A
lo"'
~~~00
avelength
in m)
Fig. 1. Comparison of the measured absorption coefficient kc for S20Fio (curve C) with that of SF6 (curveA) and that of S02F2 (curve B). The ko values for SF6 and S02F2 >are taken from reference Iii.
The ko values are given for a gas pressure of100 kPa.
Among these compounds, S20Fio Proved to be particularly stablej[4] and we were thus able to complete a previous study iii with the absorption data for this compound between 122 and 202 nm. S20Fio was specially prepared for us by a University Laboratory and its purity was
found to be higher than 99.8$l.
The absorption measurements were carried out at several S20Fioi pressures ranging from 7 Pa to 10~ Pa for wavelengths between 122 and 145 nm and from 50 Pa to 5 x 103 Pa for the
140-202 nm wavelength range using the same apparatus as that described in reference iii and in the same experimental conditions: T
= 298 + 2 K; a spectral resolution of 0.1 nm over the whole wavelength range; an uncertainty on the wavelength values of +0.05 nm.
The absorption coefficient ko was calculated from Beer-Lambert's~ law:
1=Ioexp(-ko~d)
PO
Io and I being the incident and the transmitted photon beam iniensities respectively at a
wavelength and temperature T; d the path length id
= 13.6 cm); Po " 10~ Pa and P the
absolute pressure in the absorption cell in Pa.
The ko values of S20Fio, deduced from the slopes of the plots of In (Io/I) versus P for the different wavelengths studied are displayed in Figures 1 and 2 where they are compared to those of the purest SF6 we studied and of S02F2 or SOF2 respectively taken from the previous paper iii. The uncertainty on the S20Fio absorption coefficients ias estimated to be about +10$l for the highest and the lowest values and about +6% for the others.
From Figure 1 it can be seen that S20Fio presents a greater absorption than S02F2 and
particularly than SF6 with values of ko ranging from 9.9 x 10~ m~~ (for = 121.6 nm) to 61 m~~ (for A
= 201.8 nm) with a peak at 169.5 nm (ko ~ 8.8 x 103 m~~).
The overall absorption spectrum of S20Fio however is quite sim>ilar to that of SOF2 (see Fig. 2) and even SF4 (see Fig. 5 of Ref. iii).
N°11 VACUUM ULTRAVIOLET ABSORPTION OF S20Fio 2105
ios ~
~ ~ ~~%~
~° ~
,'+ B
+~
~Q3 ~
~~
+~,
+
z io~
(
C~+
~ +
E .
~
.
m lot ,
loo
.
A
,o.,
.
10.2
100 120
Wavelength
