Aug. 4, 2004 A prototype microscope that uses neutrons instead
of light to “see” magnified images has been demonstrated at the
National Institute of Standards and Technology (NIST). Neutron
microscopes might eventually offer certain advantages over
optical, X-ray and electron imaging techniques such as better
contrast for biological samples. Described in the July 19 issue
of Applied Physics Letters,* the imaging process involves
hitting a sample with an intense neutron beam. The neutrons that
pass through—whose pattern reflects the sample’s internal
structure—are directed into a row of 100 dimpled aluminum
plates. Each dimpled plate acts like a weak focusing lens for
neutrons, diverting the neutrons’ path slightly at each
interface. The image then is projected onto a detector. Adelphi
Technology Inc. of San Carlos, Calif., designed and demonstrated
the microscope with the help of NIST scientists, who routinely
use multiple lenses to focus neutron beams for other research.
In principle, neutrons could provide