Development of a stabilized low temperature infrared absorption cell for use in low temperature and collisional cooling experiments

We have constructed a stabilized low temperature infrared absorption cell cooled by an open cycle refrigerator, which can run with liquid nitrogen from 250 to 80 K or with liquid helium from 80 K to a few kelvin. Several CO infrared spectra were recorded at low temperature using a tunable diode laser spectrometer. These spectra were analyzed taking into account the detailed effects of collisions on the line profile when the pressure increases. We also recorded spectra at very low pressure to accurately model the diode laser emission. Spectra of the R(2) line in the fundamental band of <F>13CO</F> cooled by collisions with helium buffer gas at 10.5 K and at pressures near 1 Torr have been recorded. The He-pressure broadening parameter (<F>γ0=0.3</F> cm-1 atm-1) has been derived from the simultaneous analysis of four spectra at different pressures. [Copyright &y& Elsevier]