PROGRESS IN X-RAY MICROBEAM SPECTROSCOPY

X-ray spectroscopy has been widely used for chemical analysis since it s discovery in 1895. X-ray fluorescence (XRF) has been used for over 6 0 years for identifying the elemental composition in most kinds of sam ples and in combination with modern semiconductor detector technology XRF has developed into a versatile, multi-element method. With the hig h X-ray flux attainable from the synchrotron source, new spectroscopic techniques have become available, such as extended x-ray absorption f ine structure (EXAFS) and x-ray absorption near-edge spectroscopy (XAN ES), for studying the chemical states of the different elements. With the use of high-intensity x-ray microbeams all of these different anal ytical methods can be performed on a microscopic level. By scanning th e microbeam over a sample, the distribution of different elements can be determined. A description of the basic principles of x-ray microbea m spectroscopy, and the historical background, is given and comparison s with other techniques are discussed. Different techniques for focusi ng of x-rays, detection and image reconstruction are described. Exampl es of applications and future perspectives are discussed with particul ar emphasis on capillary optical systems.