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June 2013 Print

Alastair MacDowell, Beamline Scientist, Experimental Systems Group

 

Alastair MacDowellBeamline scientist Alastair MacDowell has pioneered several hard x-ray science programs in his 17 years at the ALS. MacDowell began his career here with a directive to prove the viability of providing hard x-ray capabilities. Early in his tenure he did just that, working to establish the micro-XAS program at Beamline 10.3.2 and the x-ray microdiffraction program that ended up at Beamline 12.3.2, both of which are still in operation today.

MacDowell went on to develop many other ALS hard x-ray programs. He also proved that protein crystallography was tenable on bend-magnet beamlines, which lent vital support to the ALS superbend project and the five protein crystallography beamlines subsequently established at the ALS. MacDowell conducted the initial tomographic experiments on Beamline 7.3.3, establishing a program that moved to Beamline 8.3.2, and high-pressure x-ray diffraction experiments that led to an endstation at Beamline 12.2.2. He also implemented small-angle x-ray scattering (SAXS) at the ALS, which has remained at Beamline 7.3.3. Being involved in so many programs has its pros and cons, says MacDowell.

“If you build the equipment, then bring people in to use it, they come to you when something is broken,” he says.

MacDowell cites the “village” that makes up the ALS as key to establishing all of these programs. “They all require multiple people, from the techs to assemble, engineers to design, the ALS management and support to provide the environment, and the local scientists to provide the scientific motivation,” he says.

These days, MacDowell is in charge of the ALS tomography program at Beamline 8.3.2 and the high-pressure x-ray diffraction station at Beamline 12.2.2. At Beamline 8.3.2 MacDowell and ALS Postdoctoral Fellow Abdel Haboub are currently working on a Laboratory Directed Research and Development (LDRD) program on coded-aperture detectors and an x-ray microtomographic hot cell that allows users to research the failure of materials at very high temperatures. MacDowell and his team built the instrumentation for the hot-cell technique, which is already enabling exciting research. Notably, Berkeley Lab senior materials scientist Rob Ritchie and his team have made headlines with the research they’ve conducted at Beamline 8.3.2 using the hot-cell facility to study the heat-resistant properties of advanced ceramic composites, which show promise as next-generation jet engine materials (see a video about their research).

The hot cell, which MacDowell calls “totally novel,” is currently not available at any other synchrotron facility. Researchers are using it for a variety of research topics, including

  • Gaining a better understanding of volcanoes by monitoring the cracking of magma,
  • Studying how concrete behaves at high temperatures in order to monitor the stability of burning buildings, and
  • NASA research on heat shields for space reentry vehicles.