Ellipsoid X-ray focussing for synchrotron-radiation microprobe analysis at the SRS, Daresbury, UK

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 292; no. 3; pp. 719 - 727
• Main Authors: van Langevelde, F., Bowen, D.K., Tros, G.H.J., Vis, R.D., Huizing, A., De Boer, D.K.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.07.1990
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/0168-9002(90)90193-A

A focussing monochromator for synchrotron-radiation microprobe analysis has been made by bending and fixation of a Si(111) crystal onto an ellipsoidal mould produced by numerically controlled diamond cutting. Experiments were performed using 15 keV radiation from the SRS dipole line. Measured beam profiles, topograms and fluxes are compared with the results of a ray-tracing program. In the experiment the spot size has been reduced, if compared with a flat monochromator, by a factor of 1000 horizontally and by a factor of 15 vertically, in agreement with the calculations. The measured photon-flux density is 10 4 photons/(s mA μm 2), suited for detecting trace elements of sub-ppm concentration in an organic matrix with a detection volume of the order of 10 μm diameter.