GAS-PHASE INFRARED-SPECTROSCOPY OF N2O IN AN EQUILIBRIUM CELL AT 10-K AND 5-K

We report the extension of the collisional cooling technique from the microwave region into the infrared. This technique permits the gas phase spectra of molecules to be recorded at liquid helium temperatures. As a test of the utility of this technique for the infrared, we have observed the R(0), R(1), and R(2) lines of the (00 degrees 1 <-- 00 degrees 0) vibration-rotation band of N2O at 5 and 10 K. The Doppler linewidth was determined at each of these temperatures and also at 300 K for the R(0) line. (C) 1995 Academic Press, Inc.