Yiming Yan

X-ray spectrometry using polycapillary X-ray optics and position sensitive detector

Polycapillary X-ray optics (capillary X-ray lens) are now popular in X-ray fluorescence (XRF) analysis. Such an X-ray lens can collect X-rays emitted from an X-ray source in a large solid angle and form a very intense X-ray microbeam which is very convenient for microbeam X-ray fluorescence (MXRF) analysis giving low minimum detection limits (MDLs) in energy dispersive X-ray fluorescence (EDXRF). A new method called position sensitive X-ray spectrometry (PSXS) which combines an X-ray lens used to form an intense XRF source and a position sensitive detector (PSD) used for wavelength dispersive spectrometry (WDS) measurement was developed recently in the X-ray Optics Laboratory of Institute of Low Energy Nuclear Physics (ILENP) at Beijing Normal University. Such a method can give high energy and spacial resolution and high detection efficiency simultaneously. A short view of development of both the EDXRF using a capillary X-ray lens and the new PSXS is given in this paper.

Study of the monolithic x-ray focusing lens and its application in microbeam x-ray fluorescence analysis

A model of theoretical simulations of a monolithic x-ray focusing lens is described. These calculations are compared with experimental measurements of the lens. For the Mo Kα line, a measured focal spot diameter of lens were about 30 µm. Compared with an aperture of equivalent size located at the output focal distance without the lens, a power density gain of about 1500 was obtained. The application of the lens in microbeam x-ray fluorescence analysis reduced the minimum detection limits for transition elements down to the 10−13 g level. Copyright

New XRMF spectrometer with high resolution and high efficiency using polycapillary x-ray lens and PSPC+

A new spectrometer based on plane crystal wavelength dispersive method using a position sensitive proportional counter (PSPC) in conjunction with x-ray microbeam formed by monolithic polycapillary x-ray focusing lens has been developed. The new spectrometer could be used for XRMF analysis with high sensitivity, high spatial resolution and energy resolution simultaneously. The minimum spot sizes of the Cu-K(alpha) focused by the lens was 50micrometers . The energy resolution of 5.8 eV was obtained for Ti-K(alpha) by means of the spectrometer.

X-ray focusing system: a new x ray lens and its applications

A new X-ray focusing system--the X-ray lens composed of guiding capillaries is introduced in this paper. The principles of this lens and its potential applications in different areas are discussed briefly. The preliminary results of developing this lens and using it in XRF and X- Ray Lithography in Beijing Normal University are reported.