Applications of the VUV Synchrotron SOLEIL

St Aubin

SOLEIL : 29 beamlines

Valence-shell excitations in the gas and condensed phase DESIRS : Scientific case in the VUV (5-40 eV) 1.High resolution spectroscopy Ex : CO,CO 2, N 2, H 2, HD, D 2, He, C 2 H 4, C 2 H 2 etc… (11) 2.Spectroscopy, fragmentation and reactivity of state-selected ions Radicals : C n H y, C n F y, carbenes, benzyl(9) Astro/combustion interest : PAHs, Diamondoids, ices(4) Pre-biotics/bio-mimetics : polynes, 2-pyridone, amino-acids, DNA basis, acetamide(7) Reactivity (CERISES ) : O + +CH 4, C x H y N z ++ + CH 4 (6)  2’ : Mass spectrometry with ion traps Ex : Biopolymers (proteins, peptides, DNA sequences), organics molecules, atomic ions (9)  2’’ : Atmospheric chemistry SOA analysis by thermodesorption (1) 3.Photoionization dynamics Laser-excited species (1), autoionizing states (1) Nanoparticles & Clusters (Ar)(3) 4.Alignment, dichroism and chirality Gas phase ionization of chiral species (PECD) : organic species, amino-acids(8) CDAD/MFPADs on fixed-in-space molecules : Di-at, Tri-at, chiral molec(3) Condensed phase photochemistry on amino-acids : Leucine, Iso-valine, ices analogue (6) (homochirality of life) 5.Excitation and relaxation in the condensed phase Luminescent Solids (SiO 2 ) (4) Molecular Liquids (H 2 O, CH 3 OH) (2)  5’ : Optical properties of bulk materials and thin films with the FTS (1)

Outline The VUV FTS branch on the DESIRS beamline A wavefont division interferometer for a VUV FTS A multipurpose gas sample chamber VUV photoabsorption in a discharge cell Conclusion & Perspectives.

The FTS Branch on the DESIRS Beamline Gas sample chamber VUV FTS Nahon, L. et al. (2012). J. Synchrotron Radiat. 19, 508–520.

Principle for a scanning WD interferometer fixed reflector mirror BS Mobile reflector HeNe VUV Source VUV photodiode HeNe beamsplitter mobile reflector mirror VUV source

Main specs Spectral range : nm ( nm in exotic polarization) Undulator bandwidth :  = 6% The p parameter can be changed in-situ ( 7<p<16) Theoretical minimal instrumental linewidth : 0.08 cm -1 Ultimate resolution p

Gas sample chamber Room Temperature windowless cell + LN 2 or LHe cooling capability. Possibility to install a windowless hot cell (1000K). Max column density ~ cm -2 MgF 2 or LiF window cell, various lengths : 1 up to 40 cm. Molecular jet setup Max column density ~ cm -2

a high temperature windowless cell (< 1000 K) CO B(0)-X(0) band T ≈ 950K

Production of transient species with a windowed DC discharge cell VUV CH 3 column density determined from the CH 3 B-X band 216 nm used as a reference – absolute data from the literature. CH 3 spectrum from CH 4 + He Linewidth = 13.8 cm -1 dCH 3 ~ cm -3

Production of transient species with a windowed DC discharge cell OH spectrum from H 2 O + He B. Gans (ISMO), JC Loison (ISM), K. Hickson (ISM) OH D(0)-X(0) OH D(1)-X(0) Linewidth = 1.07 cm -1 dOH ~ 1.5x10 13 cm -3

OH D-X(v=0) band In red : simulation (PGOPHER) H2H2 Lee et al., J. Chem. Phys. 81, 31 (1984) OH D-X ?? < f < 0.013

After 7 years of operation : Topics Country of the main proposer Conclusion

Typical spectral range covered for a 9 shifts run period (72 hours) : ~ cm 0.2 cm -1

Future developments : Discharge cell (DC, RF, flow tube…) to produce transient species (radicals, highly ionized species) Developments on the molecular jet chamber On the long term : connect a VUV emission source (but spectral luminance ?) A unique tool for ultra–high resolution absorption spectroscopy in the VUV range : High spectral resolution (  = 0.08 cm -1 ) Broad spectral range covered (300-50nm) Absolute line position (~ ) High efficiency : Rare gases, diatomic molecules but not only : CO 2,H 2 O,C 2 H 2,NH 3,C 2 H 4 etc….

People who initiated the project : (1995): F. Polack et D. Joyeux LURE / Institut d'Optique M. Vervloet Lab. Photophysique Moléculaire, DESIRS beamline : L. Nahon, G.Garcia, M. Roudjane, L. Archer, B. Pilette, J.-F. Gil, K. Ito, M. Vervloet, D. Joyeux. D.Joyeux : Conception D. Phalippou : Design J.C. Rodier : Electronics G. Colas, Ch. Beurthe, J.Y Clotaire : optical realisation & metrology Franck Delmotte : Coatings