Sean M. Brennan
After 22 years as a Senior Scientific Staff member at the Stanford Synchrotron Radiation Laboratory Sean is
now Emeritus Staff and consults part time at SLAC as well as with private companies. He received his Ph.D. from
the Stanford Department of Materials Science and Engineering in 1982 and is the author or co-author
of ~170 publications.
X-ray Scattering from Thin Films, Surfaces and Amorphous Materials
Areas of research include measurement of strain in thin films deposited on
surfaces; reconstructions at surfaces and interfaces under both UHV, sputter-deposition and CVD conditions.
Short and intermediate-range order in amorphous materials including the structure of liquid water near freezing.
The advantage of the synchrotron for these experiments is the ability to tune the incident beam energy to enhance
the sensitivity of the technique to the particular element of interest.
Fluorescence Spectroscopy and X-ray Microscopy
Trace impurities have been measured in extremely small particles
and those same particles imaged using both X-ray Fluorescence and X-ray Microscopy. One
very exciting project studied particles which had been returned to earth by the Stardust NASA
project. In this mission the spacecraft swept through the tail of comet Wild-2, collecting the
particles ejected from the comet due to solar heating. These particles were captured in aerogel
and returned safely to earth. The particles were then isolated in the aerogel and studied to
determine elemental abundance as well as structural morphology.