Sample Preparation
Preparation of high quality, pure samples is very important if you are
going to study very weakly bound complexes. We have a custom built
high vacuum line (built by Roy Wentz, glassblower at the University of
Michigan) that allows transfer of high purity gas phase samples to a glass
sample bulb. The components of interest are condensed into the sample bulb
from a lecture bottle or other source in concentrations that will
lead to a 1-3% mixture when diluted to a few atm. total pressure with
a rare gas such as argon or a helium/neon mixture.
A 2 liter glass sample bulb is shown attached to
one of the outlets on the vacuum
manifold. The high vacuum is made possible by a diffusion pump that operates
on the same principles as the (much larger scale) pumps on the vacuum chamber.
The glass diffusion pump in this case is at the right of the vacuum line
and is shown below. Unlike the water cooled diffusion pumps that are a
part of the vacuum chamber, this one is air cooled although uses the same
pump oil as the larger pumps. The orange rubber tubing goes from the outlet
of the diffusion pump to a roughing pump which lives in the
cupboard under the hood.
