University of Tennessee
Materials Science & Engineering



Experiments at the Spallation Neutron Source
Oak Ridge National Laboratory, Oak Ridge, Tennessee
October 18-20, 2018




Bernadette Cladek (right), a PhD student in the Materials Science & Engineering Department at the University of Tennessee, investigates the structure of mixed CO2 and CH4 hydrates on the NOMAD beamline at the SNS. Fellow UT MSE PhD student, Dayton Kizzire, came to help Bernadette with her experiments. To successfully guide the experiments, two beamline scientists, Dr. Michelle Everett and Dr. Marshall McDonnell (left), were present for much of the three-day experiment. Coincidentally, Michelle and Marshall are graduates of the University of Tennessee, with PhDs in MSE and chemical engineering respectively. Michelle shared the same PhD advisor as Bernadette, Prof. Claudia Rawn. Marshall shared the same PhD advisor as Dayton, Prof. David Keffer.


This team pushed the NOMAD beamline to its limits, performing experiments at cryogenic temperatures (as low as 2 K) while under pressure (up to 25 atm).


The gas manifold for delivering the helium necessary for the cryostat is only slightly less complex than the process used to generate neutrons at SNS.


The sample holder had to be transferred from a bucket of liquid nitrogen into the cryostat as quickly as possible to avoid the humid Tennessee air from condensing on the sample.


ORNL Staff Scientist, Dr. Matt Tucker, is a hands-on theoretician. Dr. Keffer (in background) was mostly present for moral support!

More photos on the Keffer research group site.