for scientists to view materials on the nanoscale, the electron beam also must
be incredibly stable—vibrating no more than 25 nanometers in any direction.
That’s 1,000 times smaller than the diameter of a human hair.
“To make that beam as narrow and precise as possible, you have to have a
very gentle deviation,” Dr. Dierker says. “So one of the key ingredients for being
able to achieve a higher brightness is having a larger accelerator.”
The project team achieved the necessary brightness and stability by setting
technical specifications that pushed the cutting edge. The team also did R&D,
built prototypes and consulted with global experts from a scientific advisory
committee to make sure the new technology would meet the project’s needs.
“Peers would come in and do a very careful design review to make sure that
we were capable of building the technology, that it would operate properly at
the end and deliver the mission need,” says Mr. Crescenzo, who also served as
federal project director, or the sponsor’s on-site representative.
Through this process, the team designed a storage ring with a circumference of 792 meters ( 2,598 feet) that uses 826 large magnets to propel electrons
along a circular path. In one second, each electron will circle the ring about
375,000 times—traveling at more than 99 percent of the speed of light with
almost no vibration.
“We drew upon the expertise of scientists from around the world, including
scientists from other facilities who had recently constructed facilities and had
up-to-date experience with what the challenges were and what the alternative
options would be,” says Dr. Dierker, who is now a professor in the Department of Physics and Astronomy at Texas A&M University, College Station,
“Peers would come
in and do a very
review to make
sure that we were
capable of building
—Frank Crescenzo, U.S. Department of
Energy, Upton, New York, USA
The lab’s powerful microscope
is designed to deliver a suite of
unprecedented X-ray imaging