Laser-Generated Plasmas: Source Requirements For X-Ray Microscopy

Over the past few years microscopic imaging using X rays has been made feasible by developments in synchrotron radia-tion sources and in techniques for manufacturing X-ray optical components. However, it is clear that X-ray microscopes will not become widely available instruments if they have to rely on synchrotron radiation sources. Conventional X-ray generators give insufficient intensities to allow imaging in reasonable times, but recent work on laser-generated plasmas has shown that they can give intense bursts of X rays. In this paper the laser-generated plasma source requirements for two types of imaging, contact microradiography and scanning transmission X-ray microscopy, are discussed, with particular reference to the use of small commercially available lasers. It is demonstrated that such lasers could be of use, particularly for scanning X-ray microscopes, but that it is unlikely they will be capable of completely replacing synchrotrons as sources for X-ray microscopy.