GB1537099A - X-ray fluorescence device - Google Patents

Abstract

1537099 Electron beam apparatus; electrode materials UNITED SCIENTIFIC CORP 15 June 1976 24760/76 Heading H1D [Also in Division H5] An electron column instrument with an electron beam in vacuum is converted for X-ray fluorescence analysis by inserting in the beam a target foil 26 which emits primary monochromatic fluorescent X-rays; these emerging from either the front or rear of the foil impinge on the sample within the same vacuum chamber to generate secondary fluorescent X-rays characteristic of the sample material, detected within the same vacuum chamber. A W collimator 28, to absorb bremsstrahlung, comprising a hollow cylinder with a small aperture in its base, carrying the target foil, e.g. of pure Mo, Cu, W, Ag &c., is mounted in a recess in frame 44, rotatable on energy-dispersive X-ray spectrometer end cap 40. The frame 44 is insulated from cap 40 and is separately grounded. On rotating to bring the foil into the electron beam (coming from the top in the figure) primary X-rays emerge from the rear to excite in sample 34 on tiltable holder 35 secondary fluorescent X-rays which are received by detector 38. A filter may be inserted between collimator 28 and sample 34 to improve monochromaticity. In alternative embodiments primary X-rays from the front of the foil are used (Fig. 9, not shown), or the foil is plated directly on the sample (Fig. 10, not shown), in which case secondary fluorescent X-rays from either the front or back of the sample may be detected. Alternative target foils may be carried on a rotatable holder equipped with multiple collimators which can be aligned with the beam (Fig. 11, not shown).