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There exists considerable interest in radiation sources of high brillance in the soft and hard x-ray regime for applications in several fields of physics, material sciences, biology, and medicine. The energy of interest ranges for biological and medical applications, from the K-edge of oxygen at 0.53 keV (''water window'') to the K-edge of iodine at 33.16 keV. The first is of importance for microscopy of biological molecules and the second for coronary angiography. Electron storage rings as synchrotron radiation sources are presently the most powerful sources in this energy regime. With the advent of modern electron accelerators delivering high current low emittance electron beams with energies up to a few GeV, it was realized that they may present attractive alternative sources of intense x-rays. The interaction of these beams with matter have the potential of producing high brillance x-rays with a tuneable time structure. Processes which are of interest in this context area
