Development of a micro-XRF system for biological samples based on proton-induced quasimonochromatic X-rays
Abstract
We have developed a micro-XRF system based on a proton-induced quasimonochromatic X-ray (QMXR) microbeam for in vivo measurement of biological samples. A 2.5-MeV proton beam impinged normally on a Cu foil target that was slightly thicker than the proton range. The emitted QMXR behind the Cu target was focused with a polycapillary X-ray half lens. For application to analysis of wet or aquatic samples, we prepared a QMXR beam with an incident angle of 45° with respect to the horizontal plane by using a dipole magnet in order to bend the primary proton beam downward by 45°. The focal spot size of the QMXR microbeam on a horizontal sample surface was evaluated to be 250 × 350 μm by a wire scanning method. A microscope camera with a long working distance was installed perpendicular to the sample surface to identify the analyzed position on the sample. The fluorescent radiation from the sample was collected by a Si-PIN photodiode X-ray detector. Using the setup above, we were able to successfully measure the accumulation and distribution of Co in the leaves of a free-floating aquatic plant on a dilute Co solution surface.
- Publication:
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Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- July 2014
- DOI:
- 10.1016/j.nimb.2013.12.043
- Bibcode:
- 2014NIMPB.331..261P
- Keywords:
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- Micro-XRF analysis;
- Proton-induced quasimonochromatic X-ray;
- Polycapillary X-ray lens;
- Biological samples;
- In vivo measurement