Glass tubes for concentrating X-rays.

Glass tubes for concentrating X-rays

The control and manipulation of X-rays requires optical components considerably more sophisticated than the types of lenses and mirrors typically used to guide visible light. Soviet physicists have now developed a way of producing a concentrated X-ray beam by channeling X-rays through a bundle of hollow glass tubes, or capillaries. By guiding X-rays down their lengths, the tubes convert an initially diverging beam of X-rays into a converging beam. A prototype X-ray "lens" unveiled last week consists of 2,000 capillaries, each about 70 microns wide. This lens focuses X-rays to a spot a little less than 300 microns across.

Developed by Muradin A. Kumakhov and his colleagues at the I.V. Kurchatov Institute of Atomic Energy in Moscow, this technology may prove useful for medical imaging and the treatment of tumors in the human body, permitting clinicians to use more tightly focused X-ray beams to minimize damage to healthy tissue. Improving the technology to reduce the spot size to just a few microns would also open up the possibility of using X-rays for manufacturing integrated-circuit chips more densely packed with components than today's versions.

"We're in the process of developing the supporting technology to make these [X-ray lenses] here," says Walter M. Gibson, who heads the newly formed Center for X-ray Optics at the State University of New York at Albany. Gibson and Kumakhov head a joint research the program aimed at developing the technology further and demonstrating its feasibility for commercial applications.