SREL Reprint #2451

Overview of synchrotron X-ray sources and synchrotron X-rays

Darrell G. Schulze1 and Paul M. Bertsch2

1Agronomy Department, Purdue University, 1150 Lilly Hall, West Lafayette, IN 47907-1150
2Advanced Analytical Center for Environmental Sciences, Savannah River Ecology Laboratory,
The University of Georgia, P.O. Drawer E, Aiken, SC 29802

Introduction: The discovery of the crystalline nature of colloidal clay particles in the 1930's was a major breakthrough made possible by the then-new technique of x-ray diffraction. X-ray powder diffraction remains an essential tool for clay mineralogy research today, while other x-ray based techniques such as x-ray fluorescence spectroscopy, radiography, and computed tomography are important to individual researchers based on availability of equipment and the needs of particular research projects.
Commercially available x-ray instrumentation relies on specialized vacuum tubes as the x-ray source. The capability of sealed-tube x-ray sources has not increased significantly since Wilhelm Conrad Röntgen's discovery of x-rays a century ago. The introduction of rotating anode x-ray tubes in the 1960's brought about a 10-fold increase in x-ray intensity, but the basic constraints of a vacuum tube x-ray source, namely significant intensity over only a few narrow energy ranges and a highly divergent source, remain. Beginning in the 1950's the high energy physics community began to build particle accelerators to study the fundamental properties of matter. One type of particle accelerator, the synchrotron was designed to accelerate charged particles around a nearly circular trajectory so the particles could be made to strike a target at high energy. Synchrotrons produced large quantities of electromagnetic radiation, including x-rays, as a by-product of steering the particles around the ring. This radiated energy was originally considered a nuisance because it had to continually be replaced, but it soon became apparent that the synchrotron radiation had many useful properties for x-ray based techniques. New generations of synchrotron failures designed exclusively as x-ray sources have followed, and these powerful sources of x-rays have become important to a wide variety of scientific disciplines. . . .

SREL Reprint #2451

Schulze, D. G., and P. M. Bertsch. 1999. Overview of synchrotron X-ray sources and synchrotron X-rays. pp. 2-18 In: D. G. Schulze, J. W. Stucki, and P. M. Bertsch (Eds.). Synchrotron X-Ray Methods in Clay Science, The Clay Mineral Society.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).