19.1 A NEW CENTURY OF X-RAY AND NEUTRON OPTICS

One of Roentgen s earliest observations, shortly after his discovery of X rays in 1895,1 was that while the rays were easily absorbed by some materials, they did not strongly refract. Standard optical lenses, which require weak absorption and strong refraction, were therefore not useful for manipulating the rays. New techniques were quickly developed. In 1914, van Laue was awarded the Nobel Prize for demonstrating the diffraction of X rays by crystals. By 1929, total reflection at grazing incidence had been used to deflect X rays.2 A more detailed history of X-ray optics is presented in Volume II of this handbook,3 but the available optics for X rays still can be classified by those three phenomena: refraction; diffraction; and total reflection. Surprisingly, given that the physics governing these optics has been well known for nearly a century, there has been a recent dramatic increase in the availability, variety, and performance of X-ray optics f or a wide range of applications. This advance has been accompanied by a similar surge in the development of X-ray sources and detectors. The new abundance requires a fresh look at the problem of optimizing a wide range of X-ray and neutron applications. The development of X-ray technology has also advanced neutron science because a number of the optics and detectors are either applicable to neutrons or have inspired the development of neutron...