AILES beamline
ASSOCIATED PUBLICATION
A new, low temperature long-pass cell for
mid-IR to THz spectroscopy and synchrotron
radiation use
F. Kwabia Tchana, F. Willaert, L. Lago,
X. Landsheere, M. Chapuis, C. Herbeaux,
P. Roy, and L. Manceron*
Review of Scientific Instruments, 2013, 84(9)
(2013) art. n° 093101
* Synchrotron SOLEIL, l’Orme des Merisiers,
St Aubin BP48, 91192 Gif sur Yvette Cedex,
France
CORRESPONDING AUTHOR
➋
Examples of greenhouse
gas Infrared spectra for optical
absorption modelling.
A) C
3
H
8
. High Resolution
measurements near 11 µm
wavelength at 142K for line by
line analysis. Note the spectral
simplification at low (blue) versus
ambient (red) temperature.
B)
SF
6
. Observation (red) of the
υ
6
IR
-forbidden band in the 33 µm region
at 160K for modeling IR absorptions
(blue) of this high global warming
power gas of anthropogenic origin.
REFERENCES
[1] S.M.Chernin & E.G. Barskaya, Appl. Optics
30 (1991), 51
[2] V.Boudon et al. Phys. Chem. Chem. Phys.
16 (2014), 1415
One specific requirement implied
development of a cryogenic pressure
sensor in the sub-millibar range, for
accurately measuring the pressure of
the gases for which the profiles and
IR absorption cross-sections are being
determined. Such a device has also been
developed at SOLEIL in collaboration with
the Ultra-High Vacuum Group, and enables
in situ
measurements of pressure in the
40 to 0.1 mbar range, with 1% accuracy,
regardless of temperature.
Temperature homogeneity is another major
issue and no less than fifteen sensors
are dispatched inside the cell and ten
regulation control loops ensure a ±2°C
temperature homogeneity down to -190°C.
The first measurements were carried out
in late 2012 and this unique equipment has
allowed new observation of spectroscopic
features for a potent greenhouse gas (SF
6
)
(figure
➋
) [2]. Since then, the equipment
is now operational on the AILES beamline,
and investigating atmospheric trace gases.
A need for metrological precision
Fist results and perspectives
123
SOLEIL
HIGHLIGHTS
2013
