The attached chapter deals with the production of X rays and their mechanisms of interaction with materials. The emphasis is placed on X rays useful for diagnostic imaging, that is in the energy range between 10 and 140 keV. X-ray interactions are discussed primarily from the standpoint of imaging, as opposed
to diffraction or spectroscopy. Brief coverage of important developments not
yet clinically utilized, such as synchrotron and plasma X-ray sources, is also
included. Because these sources produce radiation over a wide spectral range,
including intense soft X rays useful for biological X-ray microscopy, microtomography and spectroscopy, production and interaction of low-energy X rays are discussed, though in considerably less depth. Though electron-impact
sources are still used to produce most X rays used in clinical applications and
for biomedical research, the unique properties of some of the newer devices,
most notably laser-produced plasma and synchrotron X-ray sources, have
made possible discoveries which never would have been made in their
absence. As these sources become ever cheaper and more efficient, they are
certain to have an important impact in basic research, and possibly in clinical
practice as well.