" New Way of 'Seeing': A 'Neutron Microscope' "

["Jaro" <jaro-10kbq@sympatico.ca>]

http://www.physorg.com/news599.html

New Way of 'Seeing': A 'Neutron Microscope'

July 30, 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 better image resolution than visible

light because they have shorter wavelengths.as short as 1 nanometer (nm)

compared to 400-700 nm. In this demonstration at NIST.s Center for Neutron

Research, the microscope produced a resolution of only 0.5 millimeters and a

magnification of about 10. However, Adelphi hopes to substantially improve

image resolution through research to reduce lens aberrations. The company

also hopes to build a compact, laboratory-scale neutron source.



Moreover, neutrons offer some unique advantages. Unlike other imaging

methods, neutrons interact strongly with hydrogen, an important component of

biological samples composed mostly of hydrocarbons and water. And neutrons

easily penetrate samples, thereby reducing artifacts produced with other

techniques requiring thin slices, staining or fixing.



Stanford University also participated in the research, which was supported

in part by the U.S. Department of Energy.

---

Outgoing mail is certified Virus Free.

Checked by AVG anti-virus system (http://www.grisoft.com).

Version: 6.0.726 / Virus Database: 481 - Release Date: 7/22/2004



************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/