A molecular iodine atlas in ascii format Houssam
- Slides: 9
A molecular iodine atlas in ascii format Houssam Salami and Amanda Ross Laboratoire de Spectrométrie Ionique et Moléculaire, Université Lyon I & CNRS (UMR 5579) Villeurbanne, France. An invitation to use a Doppler-limited absorption spectrum, available on the Web …
Why record (yet another) spectrum of the B-X transitions of I 2? Not for the B-X spectroscopy of iodine! Only to calibrate excitation spectra. The information already exists : 1) Aimé Cotton Atlas of Gerstenkorn and co-workers (in four parts). § In paper format § Corrections are required at short wavelengths. 2) Sub-Doppler Atlas (Katô and co-workers) « Hors Concours » 3) From tabulated parameters. (calculated spectrum, e. g. commercial Iodine Spec)
Our motivation : an excitation spectrum of Ni. H fluorescence, ~17400 cm-1. Nice spectrum. Inadequate wavemeter / temperature stabilized F-P fringes.
Recording the absorption spectrum of I 2 Transmission spectrum recorded in 4 pieces (with appropriate optical filters). Instrumental resolution 0. 02 cm-1. 50 cm iodine cell, heated according to wavelength region of interest.
I 2 B-X absorption spectrum Reference He. Ne laser
Close Up … Doppler limited iodine lines still have odd shapes!
How does the calibration compare with other sources ? Circles : LASIM – Aimé Cotton atlas Triangles : LASIM – Katô atlas
Applied to an excitation spectrum of Ni. H Q (3 ½) Comparison reveals non-linear scan of the laser, but calibration is quite feasible. Q (2 ½)
Conclusion The spectrum was recorded to solve a local problem, but could probably prove useful elsewhere. It is freely available … We’re working on software to calibrate from this atlas automatically. Has been submitted to Journal of Molecular Spectroscopy.
