Last September, two undergraduate
students were fortunate to be invited to a joint project between both Prof.
Andrew Ault’s and Prof. Pratt’s research groups, through the University of
Michigan Undergraduate Research Opportunity Program. The project intends to
establish a protocol for imaging and analyzing snow crystals for climate
research, specifically the impurity concentration and distribution in Arctic
snow.
We intend to use the Raman
spectrometer detailed in the previous December blog post “Raman Installation”
for its imaging and elemental mapping capabilities. It is an exciting prospect
to be among the first in utilizing Raman on snow crystals, however, we have run
into several complications. The Ault group’s Raman spectrometer features a
laser filter that can control its intensity. Higher settings generally result
in increasing base resolution for imaging. Unfortunately, a high filter setting
is a dual-edged sword as the laser will heat up samples. In our test run with
the Raman, the laser burnt through the silicon sample several times! We will
most likely use a low filter setting despite the base resolution drop.
 |
| Linkam Stage (Placeholder for lab one) |
A more immediate complication is
the tendency for snow to melt, especially under the Raman’s laser. We’ve made
progress in the last two months in finding a way to preserve the snow crystals
long enough for Raman analysis. A Linkam cooling stage is in the Ault Lab which
will allow us to keep samples at a stable -30°C during imaging.
The Lab also has a recirculating
cooler which will be paired with the Linkam stage once the necessary bath
fluids are ordered. Soon after, we will be ready to begin determining
parameters for imaging.
 |
| Placeholder for Freezer/Snow |
The Ault Group has snow that is kept in the new freezers mentioned previously in
the blog. It will be used along with natural Ann Arbor snowfall until we are
ready to analyze our Arctic snow currently in storage. Hopefully we will
continue updating our progress as we come closer to the Undergraduate Research
Symposium in April!
