Biomedical Engineering Reference
In-Depth Information
(a)
Figure 11.9 (See color insert following page 302) Tanida imaging system: (a) schematic, (b) device, (c)
sample images. (From Tanida, J., Shogenji, R., Kitamura, Y., Yamada, K., Miyamoto, M., and Miyatake, S. Optics
Express 2003: 11(18), 2109-2117. With permission.)
use concave mirrors, but the majority of x-rays pass through unaffected. Only at glancing angles
are x-rays reflected in this manner, leaving conventional x-ray telescopes with only a 1 8 field of
view. A lobster eye design, on the other hand, has the potential for a nearly unlimited field of view.
However, interest waned until Australian scientists revived the idea in 1989 and research
began in earnest for a working device. While these attempts have not yet come to fruition, support
for the concept of using lobster eyes has spread internationally and expanded to include
satellite astronomy (Peele et al., 1996) and computer microchip processing (Chown, 1996a,b).
Peele et al. have demonstrated x-ray focusing using microchannel plates manufactured by
LIGA (lithographie, galvanoformung, abformung) processing of poly-methyl-methacrylate
(PMMA). In the case of microchip technology, the lobster eye design is used in reverse to produce
parallel x-rays (Figure 11.15). Traditionally, circuit linewidths are defined by light, with shorter
wavelengths allowing smaller electronics. The wavelengths of x-rays are well-suited to this
application, but it has proven difficult to generate parallel x-rays. The lobster eye design may be
a feasible solution.
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