Knowledge Bank

We have recently reported a technique for collisional cooling of gas phase samples to liquid helium $temperature.1$ In this paper we report the implementation of this method at liquid nitrogen temperature. This is easier and offers a wider range of straightforward spectroscopic applications than the liquid helium implementation. By use of a heated injector and a variable temperature cell it is possible to separate the vibrational and rotational temperatures of a spectroscopic sample so that they may be varied independently of one another. A comparison of experiment to theory on some transitions of methyl flouride ($\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CH3F$) is used to illustrate this experimental technique.