A tight squeeze for high-energy X-rays.A tight squeeze for high-energy X-rays To delve into the nooks and crannies Noun 1. nooks and crannies - something remote; "he explored every nook and cranny of science" nook and cranny detail, item, point - an isolated fact that is considered separately from the whole; "several of the details are similar"; "a point of information" of materials whose structures are not well known, scientists often turn to X-rays. Using diffraction, spectroscopy, and small-angle X-ray-scattering techniques, they can reveal the makeup of molecules and materials as diverse as the human cold virus, the enzyme HIV-1 reverse transcriptase Reverse transcriptase Any of the deoxyribonucleic acid (DNA) polymerases present in particles of retroviruses which are able to carry out DNA synthesis using an RNA template. , some high-temperature superconductors, and many crystals. Now, scientists report the highest-resolution scanning X-ray image ever made with hard X-rays hard x-rays x-rays of shorter wavelength. hard x-rays Radiation physics Short wavelength, high-frequency and highly penetrating megavolt range–eg, produced by 60Cobalt–X-rays used in RT or generated by nuclear 'incidents'. Cf Soft X-rays. . Physicist Donald H. Bilderback of Cornell University and his colleagues report using tapered glass capillaries to condense con·dense v. con·densed, con·dens·ing, con·dens·es v.tr. 1. To reduce the volume or compass of. 2. To make more concise; abridge or shorten. 3. Physics a. high-energy X-rays into ultrasmall beams, providing "unprecedented spatial resolution (Data West Research Agency definition: see GIS glossary.) A measure of the accuracy or detail of a graphic display, expressed as dots per inch, pixels per line, lines per millimeter, etc. It is a measure of how fine an image is, usually expressed in dots per inch (dpi). " in some materials. They describe their work in the Jan. 14 SCIENCE. "This isn't like making an optical image with a lens, as in a camera or microscope," Bilderback says. "A better analogy is a funnel. We're concentrating, or squeezing, the beam down from a big size to a small size, making a thin stream from a thick one, the way a funnel does with water." To make such an X-ray concentrator, the scientists heated lead glass tubing, then drew out needle-like ends. They then etched a thin gold film with lines 300 nanometers wide. Using the Cornell High-Energy Synchrotron synchrotron: see particle accelerator. synchrotron Cyclic particle accelerator in which the particle is confined to its orbit by a magnetic field. The strength of the magnetic field increases as the particle's momentum increases. Source for X-rays, they first scanned the film's surface with a beam that was 95 nanometers wide and had an energy range of 5 to 8 kiloelectron-volts. With these tools, they could resolve details on the gold film as small as 50 nanometers wide. Then, using a slightly wider beam of 360 nanometers, they performed a Laue diffraction on a tiny crystal. There, they successfully resolved the smallest sample ever probed by X-ray diffraction - a volume measuring five one-thousandths of a cubic micrometer micrometer (mīkrŏm`ətər, mī`krōmē'tər). 1 Instrument used for measuring extremely small distances. . "Now that we have these small images, we can move other X-ray diffraction techniques down to this scale. From that point of view, it's a breakthrough," Bilderback says. "This technique will be important to material scientists, polymer chemists, or anyone interested in atomic structure. This work will have future payoff in many research areas." |
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