SPECTRAL SIMPLIFICATION BY ENCLOSIVE FLOW COOLING .1. FT-IR SPECTROSCOPY OF SUPERCOOLED GASES AT 100 K

For the simplification of molecular spectra and increase of spectral line intensity the enclosive flow cooling technique was developed. The vertical cell arrangement only needs one warm window and proved to be robust and easy to manage. In this work, the room temperature absorption spectra of CO2, CH4 and CHF3 are compared with the spectra at 100 K. The theoretically expected spectral simplification effects could be verified. As opposed to supersonic jet cooling, the optical absorption efficiency of the method is several orders of magnitude higher. Furthermore, the new cooling technique offers promising applications in generation and spectroscopy of molecular clusters, in trace gas analysis and in simulation of low-temperature processes in the atmosphere of the Earth and other planets.