Application of Three Dimensional Confocal Micro X-Ray Fluorescence Technology Based on Polycapillary X-Ray Lens in Analysis of Rock and Mineral Samples
LI Fang-zuo1, 2, 3, LIU Zhi-guo1, 2, 3, SUN Tian-xi1, 2, 3*, YI Long-tao1, 2, 3, ZHAO Wei-gang1, 2, 3, HE Jia-lin1, 2, 3, PENG Song1, 2, 3, WANG Li-li1, 2, 3, ZHAO Guang-cui1, 2, 3, DING Xun-liang1, 2, 3
1. The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing 100875, China 2. College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China 3. Beijing Radiation Center, Beijing 100875, China
Abstract：Confocal three dimensional (3D) micro X-ray fluorescence (XRF) spectrometer based on a polycapillary focusing X-ray lens (PFXRL) in the excitation channel and a polycapillary parallel X-ray lens (PPXRL) in the detection channel was developed. The PFXRL and PPXRL were placed in a confocal configuration. This was helpful in improving the signal-to-noise ratio of the XRF spectra, and accordingly lowered the detection limitation of the XRF technology. The confocal configuration ensured that only the XRF signal from the confocal micro-volume overlapped by the output focal spot of the PFXRL and the input focal spot of the PPXRL could be detected by the detector. Therefore, the point-to-point information of XRF for samples could be obtained non-destructively by moving the sample located at the confocal position. The magnitude of the gain in power density of the PFXRL was 103. This let the low power conventional X-ray source be used in this confocal XRF, and, accordingly, decreased the requirement of high power X-ray source for the confocal XRF based on polycapillary X-ray optics. In this paper, we used the confocal 3D micro X-ray fluorescence spectrometer to non-destructively analyzed mineral samples and to carry out a 3D point-to-point elemental mapping scanning, which demonstrated the capabilities of confocal 3D micro XRF technology for non-destructive analysis elements composition and distribution for mineral samples. For one mineral sample, the experimental results showed that the area with high density of element of iron had high density of copper. To some extent, this reflected the growth mechanisms of the mineral sample. The confocal 3D micro XRF technology has potential applications in such fields like the analysis identification of ore, jade, lithoid utensils, “gamble stone” and lithoid flooring.
[1] Shand C A, Wendler R. Journal of Geochemical Exploration, 2014, 143: 31. [2] Osán J, Kéri A, Breitner D, et al. Spectrochimica Acta Part B, 2014, 91: 12. [3] Geil E C, LeBlanc S A, Dale D S, et al. Journal of Archaeological Science, 2013, 40(12): 4780. [4] Papadopoulou D N, Zachariadis G A, Anthemidis A N, et al. Talanta, 2006, 68(5): 1692. [5] Kocot K, Sitko R. Spectrochimica Acta Part B, 2014, 94-95: 7. [6] Peng Song, Liu Zhiguo, Sun Tianxi, et al. Analytical Chemistry, 2014, 86(1): 362. [7] Sun Tianxi, Liu Zhiguo, Ding Xunliang, et al. Applied Spectroscopy, 2011, 65(12): 1398. [8] Sun Tianxi, Liu Zhiguo, Ding Xunliang. Nuclear Instruments and Methods in Physics Research Section A, 2010, 622(1): 295. [9] Lühl L, Mantouvalou I, Schaumann I, et al. Analytical Chemistry, 2013, 85(7): 3682. [10] Kouichi Tsuji, Kazuiiko Nakano. Journal of Analytical Atomic Spectrometry, 2011, 26: 305. [11] LIU He-he, LIU Zhi-guo, SUN Tian-xi, et al(刘贺贺，刘志国，孙天希，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2013, 33(11): 3147. [12] Ramos S S, Carbo A D, Adelantado J V G, et al. Talanta, 2008, 74: 1592. [13] Kanngie?er B, Karydas A G, Schutz R, et al. Nuclear Instruments and Methods in Physics Research Section A, 2007, 264: 383. [14] Elizabet A P, María T L M, Margarita E V T, et al. Talanta, 2014, 124: 79. [15] Takafumi I, Kouji T, Norio S, et al. Journal of X-Ray Science and Technology, 2011, 19: 313. [16] Sun Tianxi, Ding Xunliang, Liu Zhiguo, et al. Spectrochimica Acta Part B, 2008, 63: 76. [17] Song Peng, Zhiguo Liu, Tianxi Sun, et al. Nuclear Instruments and Methods in Physics Research A, 2013, 729: 565.
