<title>Status of the King's College laboratory x-ray microscopes</title>

Abstract

Two laboratory scale x-ray microscopes using laser generated plasma sources are being developed at King's College. One system uses dark field imaging while the other is a scanning x-ray microscope and progress with both is described. In particular, preliminary results from an extensive characterisation of the laser plasma source at the Lasers for Science Facility, CLRC Rutherford Appleton Laboratory, are discussed. This characterisation has shown that the source is eminently suitable for x-ray microscopy.

Laser plasma x-ray line spectra fitted using the Pearson VII function

“…Comparison of the first-and higher-order spectral line fits allows the diffraction grating efficiencies to be determined [1]. The variation of the first-order efficiency with wavelength is shown in figure 5.…”

“…The details of the experiments carried out to characterize the LGP source at RAL have been described elsewhere [1], and so will only be discussed briefly here. The Nd:YAG/Dye/KrF laser system delivers a train of up to eight 7 ps pulses within a 25 ns envelope at a wavelength of 248 nm and a repetition rate of up to 100 Hz (12 Hz was used for the work described here).…”

“…Laser-generated plasma (LGP) x-ray sources provide an attractive alternative to synchrotrons for applications, such as x-ray microscopy, in which a laboratory-based (rather than facility-based) system is ideally required. With this in mind, a full characterization of the LGP source at the Lasers for Science Facility (LSF) at the Rutherford Appleton Laboratory (RAL) has been carried out [1]. The main target material, Mylar tape, provides strong line emission in the water-window part of the soft x-ray spectrum, i.e.…”