HAL Id: jpa-00227012
https://hal.archives-ouvertes.fr/jpa-00227012
Submitted on 1 Jan 1987
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.
A POWERFUL TOOL TO STUDY COLLISIONAL PHENOMENA AND FOR COMBUSTION
APPLICATIONS : THE HIGH RESOLUTION STIMULATED RAMAN SPECTROSCOPY
B. Lavorel, G. Millot, R. Saint-Loup, M. Gonze, J. Santos, H. Berger, J.
Bonamy, D. Robert
To cite this version:
B. Lavorel, G. Millot, R. Saint-Loup, M. Gonze, J. Santos, et al.. A POWERFUL TOOL TO STUDY
COLLISIONAL PHENOMENA AND FOR COMBUSTION APPLICATIONS : THE HIGH RESO-
LUTION STIMULATED RAMAN SPECTROSCOPY. Journal de Physique Colloques, 1987, 48 (C7),
pp.C7-761-C7-762. �10.1051/jphyscol:19877187�. �jpa-00227012�
JOURNAL DE PHYSIQUE
Colloque C7, supplBment au n012, Tome 48, ddcembre 1987
A POWERFUL TOOL TO STUDY COLLISIONAL PHENOMENA AND FOR COMBUSTION APPLICATIONS : THE HIGH RESOLUTION STIMULATED RAMAN SPECTROSCOPY
B. LAVOREL, G. MILLOT, R. SAINT-LOUP, M.L. GONZE, J. SANTOS, H. BERGER, J. BONAMY" and D. ROBERT*
Laboratoire de Spectronomie Moleculaiz-e et Instrumentation Laser, Universite de Bourgogne. 6 , Ed Gabriel, F-21000 Dijon, France
" ~ a b o r a t o i r e de Pnysique Mol&culaire. Universite de Franche-Comtk, F-25030 Besancon Cedex, France
The stimulated Raman spectroscopy offers a great advantage over the other coherent Raman techniques: the Raman profile is obtained without distortion as in spontaneous Raman spectroscopy. That's why in the five last years, most of high- resolution investigations to study the pressure and temperature dependence of the Raman profiles have have been achieved on stimulated Raman spectrometers.
Applications in combustion media in view of temperature meas~lrements in engines or reactors have motivated several studies on molecular nitrogen because of its simple spectroscopic properties. An accurate temperature and concentration deter- mination requires the knowledge of the pressure and temperature deptndences of the N Q-branch shape.
2
Collisional broadening coefficients of the N Q-branch were accurately measured@) 2
in the temperature range 295-1310K on the stimulated Raman spectrometer of DIJON, dhereas these coefficients were determined in Besan~on University from semi-clas- sical calculations taking into account close collisions. The latter are in good agreement with the experimental values
,
and can be extended to higher tempe-0 7 d , I "
r
rature (up to 2500K) and also to higher values of the rotational quantum number
This set of colli.siona1 linewidths large information on the rotational cross-sections i.e. the line coupling parameters of
I . . . , ; 1 ; + * . i t Q(J) lines, which play a crucial role
' I l l , , , ,
collapse in a structureless
a i I band at high pressnre.
1
Indeed, for most simple molecules0 2 6 8 ' 0 12 t(r I6 $ 8 20
1 ( N 2 , CO, C02, H 0) even at atmospheric
2
- Measured (points) and caiculated (solid line) pressure, the observed Q-branch exhibik collisional broadening coefficient as a funciion ot'J for each
explored temperature. 3 collisional narrowing which nessitats
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19877187
C7-762 JOURNAL DE PHYSIQUE
the study of line coupling effects resulting from rotational population energy transfers.
Until recently, the line shift on N2 was not taken into account. Our measure- ments at 295K over the density range 0.02
-
0.8 Amagat lead to a mean shift value equal to-
5.5 x l ~ - ~ c m - ~ / ~ m a g a t ( 2 ).
At high temperature, the great number of ~opulated levels makes unrealistic the calculation of all the rotational transfer rates. This situation has motivated several authors to develop models for the rotational energy transfer rates.
So, our data (experimental and calculated) on linewidths and lineshifts have been used to perform tests of collisional narrowing models. Among several fitting laws we found that the EGL model proposed by KOSZYKOWSKI et
&.
(3) is well adapted for the description of collisional narrowing in N2.RWAN SXti7 ( CM-1 1 RAMN SillFT ( CR-i I
(1) B. LAVOREL, G. MILLOT, R..SAINT-LOUP, C. WENGER, H. BERGER, J.P. SALA, J. BONAMY and D. ROBERT, J. Physique 47 (1986) 417.
(2) B. LAVOREL, R. CHAUX, R. SAINT-LOUP and H. BERGER, Opt. Comm. 6 2 (1987) 25.
(3) M.L. KOSZYKOWSKI, L.A. RAHN and R.E. PALMER, J. Chem. Phys.
