Progress with the King's College Laboratory scanning X-ray microscope

Abstract

Since XRM99, when the first results from the King's College laboratory scanning x-ray microscope were reported, the microscope has been redesigned to enhance its Performance. The new features include scanning the laser beam, using galvanometer mirrors, to replace source scanning. The mirrors can be scanned at up to 800 Hz, with negligible noise, so that the rate-limiting factor will be the repetition rate of the laser used to form the plasma source. A mechanism to tilt the tape target surface to give a vertical x-ray beam, i.e.. horizontal specimen mounting, has also been incorporated, and a comparison of source emission characteristics in the horizontal and vertical directions has been made. Previously, image quality was limited by laser and plasma generated noise, which could not be removed with direct x-ray detection. An indirect detection system is therefore undergoing tests. Finally, development of the microscope has been hampered by limited access to the lasers at the Rutherford Appleton Laboratory, and so a new laser system has been specified and ordered for installation at King's.