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Performance of Second 50 Completed ATP Projects — Status Report Number 3 NIST Special Publication 950-3 (January 2006)
ATP Funds New Technology to Focus X-Rays and Neutrons "At the time we started with ATP, there had never been a useful example of this technology anywhere in the world," stated David Gibson, chief executive officer of X-Ray Optical Systems (XOS). He was referring to a new method for focusing x-rays and neutrons. Mr. Gibson tried to attract investors to his start-up company; however, with no proven product, he was unable to find seed money. Polycapillary optics may facilitate new x-ray andneutron applications for medical therapy, x-ray Then, in 1990, Mr. Gibson read about ATP in an industry magazine and was immediately intrigued by ATP's unique willingness to fund high-risk technologies in need of incubation. He proposed his idea to ATP and received an award in 1992. With ATP co-funding, XOS successfully developed, tested, and perfected a new technology for focusing x-rays and neutrons by reflecting them in orchestrated arrays through thousands of tiny, curved glass optic tubes capable of controlling radiation from a divergent beam. Multifiber polycapillary optics, which were developed through this project, are an enabling technology geared toward providing high-end x-ray and neutron components to analytical instrument original equipment manufacturers (OEMs) to increase their efficiency, mobility, and cost effectiveness. Polycapillary optics may be integrated with other components to facilitate new x-ray and neutron applications for medical therapy, x-ray fluorescence, mammography, lithography, and protein crystallography. With XOS's optics, a significant portion of the x-rays or neutrons emitted from a point source can be controlled to produce a collimated beam of radiation, enabling the acquisition of more detailed images at a lower radiation dosage. These tiny collimating optics continue to be a revolutionary factor in many types of diffraction applications. Primitive versions of polycapillary optics, which were developed in the late 1970s, were wholly unreliable and, therefore, were not widely adopted. During the time XOS was working to refine its manufacturing techniques, Russian, Chinese, and Japanese labs were attempting to refine polycapillary optics models, but they met with lackluster results. XOS Focuses on Polycapillary Optics XOS's research and development (R&D) efforts focused on two types of optics:
The major obstacle was getting thousands of Monolithic polycapillary optics involve a different process. Individual capillaries are fused together, eliminating the need for tiny framed screens and frame supports. The monolithic optics vary in length, yet are smaller and more compact than multifiber polycapillary lenses. Moreover, they have the ability to form tighter beams for collimating purposes and smaller spot sizes for focusing purposes.
Overcoming Technical Problems of Capillary Arrays Polycapillary optics are based on arrays of microscopic glass tubes that direct beams toward a desired focal point or to a parallel beam. Because x-rays have such high energy, however, they pass through most materials without interacting with them. XOS found that if the curvature of the capillary is kept below a certain critical limit, the x-rays reflect off the inside surfaces of the capillary, skipping like a rock across a pond. Capillary arrays can capture convergent, as well as parallel, x-ray beams and can focus or redirect their energy, thus reducing measurement times, improving spatial resolution, and increasing sensitivity. Lab experimentation early in the development of this new technology showed that capillary arrays could focus high-energy x-rays. The lingering problem was how to make it happen consistently and without having to face recurring technical imperfections. The major obstacle was getting thousands of string-like hollow glass tubes to bend at a precise, uniform, and reliably proper arc. XOS faced another obstacle in that all existing polycapillary optics were made outside the United States. No component manufacturer was able to reliably and consistently mass-produce polycapillary collimators that were able to focus x-rays with any legitimate control. Finding Alternative Materials that Withstand Wear and Tear XOS conducted a thorough materials analysis to discover which materials could withstand relatively intense x-ray and neutron beam irradiation over long periods. Over time, most types of materials deteriorate from continued contact with neutrons and x-rays. Through the ATP-funded project, XOS successfully identified and developed new glass-type materials that are less susceptible to x-ray degradation. Medical Imaging Applications Polycapillary optics able to scan large areas have applications in soft-tissue imaging, specifically mammography and angiography. The effectiveness of this type of medical imaging depends on image contrast and resolution. Once the technology evolves and allows larger scans, polycapillary optics are expected to enhance image quality in mammographic systems by serving as a scatter-control component. Polycapillary optics can also help medical technicians and researchers detect tumors that are smaller than those currently detected, and this capability will improve as scanning areas increase. Because only relatively small areas of a sample can be imaged at one time, polycapillary optics are currently more suited for research than for use in doctors' offices. Therefore, only university hospitals and laboratories have been the early purchasers of XOS equipment. ATP's Contribution Advances Technology by a Decade "Without the ATP project, XOS would be at least a decade behind where it is today," Mr. Gibson stated. "And any commercial success from these new technologies most likely would not have originated in the U.S." The ATP-funded project helped to build up a small start-up company, attracted strategic partnerships with private investors and collaborators, and, most importantly, dramatically accelerated the pace of technology development. Currently, two of XOS's customers are OEMs that use the technology for high-resolution imaging of small areas. Conclusion After receiving the ATP award, XOS further developed the technology and attracted the interest of private investors. In addition, the ATP project laid the groundwork for several follow-on contracts with other government agencies that enabled the company to pursue different applications of the technology. This effort resulted in two new, improved lenses and imaging methods for use in high-resolution imaging machines. Moreover, the company has received several industry recognition awards as well as seven patents.
Research and data for Status Report 91-01-0112 were collected during July - September 2002. Return to Table of Contents or go to next section of Status Report No. 3. Date created: April 4, 2006 |
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ATP website comments: webmaster-atp@nist.gov / Technical ATP inquiries: InfoCoord.ATP@nist.gov. NIST is an agency of the U.S. Commerce Department |
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