光谱学与光谱分析 |
|
|
|
|
|
Research on Spectral Characteristic of Miniature X-Ray Tube and Determination of Beryllium Window Thickness |
GU Yi1, 2, 3, XIONG Sheng-qing1*, GE Liang-quan3, FAN Zheng-guo1, ZHANG Qing-xian3, ZHU Zhen-ya4 |
1. China Aero Geophysical Survey & Remote Sensing Center for Land and Resources,Beijing 100083, China 2. China University of Geosciences (Beijing),Beijing 100083, China 3. The College of Applied Nuclear Technology and Automation Engineering, Chengdu University of Technology,Chengdu 610059, China 4. The School of Water Resources and Environment, Shijiazhuang University of Economics,Shijiazhuang 050031, China |
|
|
Abstract Applying Monte Carlo method, the present paper simulates the emitted X-ray spectrum of miniature X-ray tube with thirteen thickness of beryllium window in the range from 50 to 500 μm. By analyzing the characteristic of the spectrums, the reasonable choice of thickness of beryllium window relies on the application and for the beryllium window it is not the thinner the better. Taking in-situ EDXRF as an example, though the emission X-ray intensity is higher as the thickness of the beryllium window becomes thinner, the proportion of useless low-energy X-ray (<5 keV) intensity to all energy X-ray intensity also is higher (>20%). The accuracy of in-situ EDXRF will be reduced when the high-throughput low-energy X-ray enters the detector. Therefore, this paper puts forward several parameters as judgment index for beryllium window thickness, which is described as follows: ①The intensity ratios of the K-series X-ray to middle-energy (5~25 keV) bremsstrahlung and middle-high-energy (5~50 keV) bremsstrahlung (F1 and F3); ②The intensity ratios of useless low-energy X-ray (<5 keV) to middle-energy (5~25 keV) X-ray and middle-high-energy (5~50 keV) X-ray (F2 and F4), it can reflect the relative intensity of useless low-energy X-ray. The simulation results demonstrate that with the increase in the beryllium window thickness, the value of F1 (F3) improves slowly, and the value of F2 (F4) decreases rapidly. In addition to the judgment index discussed above, and considering the X-ray shielded by beryllium window, the beryllium window of miniature X-ray tube can be determined. Based on simulation analysis, the thickness of around 250μm is appropriate to miniature X-ray tube applied in the in-situ EDXRF. Comparing the emitted spectrum with 50 μm-thick beryllium window, 71.66% of low-energy X-rays are shielded, only 21.31% of X-rays with energy from 5 to 50 keV is shielded, the intensity ratio of low-energy X-ray to total energy X-ray is less than 10%, and the intensity proportion of K-series X-ray to middle-high energy X-ray maintains a high level. In other words, when the mobile X-ray source with 250 μm beryllium window is used in the in-situ EDXRF, proportion of effective signal is higher, and effect of energy resolution of the detection is least; Moreover, the relative intensity of the excitation spectral scattering background, which is obtained by detection for specimen excitation analysis, will remain at low level, thus to ensure the precision of the result of element analysis. For the beryllium window in the application of radiation therapy, the thicker the better. At this time, low-energy X-ray flux maintains a high level, and it can ensure that radiation dose is concentrated on treatment tissue.
|
Received: 2013-03-23
Accepted: 2013-06-25
|
|
Corresponding Authors:
XIONG Sheng-qing
E-mail: guyias@163.com
|
|
[1] JI Xin-ming, WANG Jian-ye, JIA Wen-hong(纪新明, 王建业, 贾文红). Acta Optica Sinica(光学学报), 2006, 26(4): 634. [2] JI Ang, ZHUO Shang-jun, LI Guo-hui(吉 昂, 卓尚军, 李国会). Energy-Dispersive X-Ray Fluorescence Analysis(能量色散X射线荧光光谱). Beijing: Science Press(北京: 科学出版社), 2011. [3] JI Ang(吉 昂). Rock and Mineral Analysis(岩矿测试), 2012, 31(3): 383. [4] LU Yan, HUANG Ning(卢 艳,黄 宁). Nuclear Techniques(核技术), 2012, 35(10): 751. [5] Moxtek, Inc. Mobile Miniature X-Ray Source. United States, 2002, Patent No: US6661876B2. [6] Pells P A, Feng Liangyuan, Small J A. X-Ray Spectrometry, 1985, 14(3): 125. [7] DAN Han-lei, ZHANG Ya-li, ZHANG Ji-ren(但汉雷, 张亚历, 张积仁). Chin. J. Radiat Oncol.(中华放射肿瘤学杂志), 2002, 11(4): 293. [8] West M, Ellis A T, Potts P J, et al. Journal of Analytical Atomic Spectrometry, 2011, 26: 1919. [9] Lemberge K, Van Espen P J, Vrebos B. X-Ray Spectrometry, 2000, 29: 297. [10] ZHANG Jing, XIE Ya-ning(张 静, 谢亚宁). Nuclear Techniques(核技术), 2004, 7(27): 497. [11] Cesareo R, Brunetti A, Castllano A, et al. Portable Equipment for X-ray Fluorescence Analysis∥Tsuji K, Injuk J, van Grieken R. X-Ray Spectrometry: Recent Technological Advances. John Wiley & Sons,2004. 30. [12] Kulshreshtha S K, Wagh D N, Bajpei H N. X-Ray Spectrometry, 2005, 34: 200. [13] Willis J P, Lachance G L. X-Ray Spectrometry, 2004, 33: 181. [14] Harada M, Sakurai K. Spectrochim Acta B, 1999, 54: 29. |
[1] |
WANG Lin, MA Xue-jie, MENG Dan-rui, LIU Rong*, XU Ke-xin. Simulation and Experiment Study on Three-Dimensional Coordinate Outlier Detetion Method[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(09): 2774-2779. |
[2] |
CHENG Feng1, 2, GU Yi1, 2*, GE Liang-quan1, 2, ZHAO Jian-kun1, LI Meng-ting1, ZHANG Ning1 . The Research on Matrix Effect and Correction Technology of Rock Sample in In-Situ Energy Dispersive X-Ray Fluorescence Analysis[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2017, 37(03): 919-923. |
[3] |
LI Zhe1, TUO Xian-guo2,3*, SHI Rui1 . Broadening Technique for Monte Carlo Simulated Element Characteristic X-Ray Spectrum [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(06): 1693-1697. |
[4] |
DONG Yan-fei1, 2, LU Qi-peng1*, DING Hai-quan1, GAO Hong-zhi1 . Study on the Best Detector-Distance of Noninvasive Biochemical Examination by Monte Carlo Simulation[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(04): 942-946. |
[5] |
YANG Qiang, GE Liang-quan, GU Yi, HUA Yong-tao, LUO Yao-yao . Theoretical Calculation and Simulation Research on Micro X-Ray Tube Target Thickness and Spectra [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2013, 33(04): 1130-1134. |
[6] |
ZHOU Guan-hua1,2, TIAN Guo-liang3, CHEN Jun4, LI Jing5, GONG A-du5* . Research of Coupling Effects among Various Water Quality Components [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(02): 470-475. |
[7] |
WANG Zhi-jun,DONG Li-fang,LI Pan-lai,SHANG Yong. Characteristic of Optical Emission Spectrum in Electron-Assisted Chemical Vapor Deposition of Diamond[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2008, 28(04): 763-765. |
[8] |
WANG Zhi-jun,LI Pan-lai,SHANG Yong,HE Ya-feng,RAN Jun-xia. Effect of Substrate Temperature on Optical Emission Spectra in Electron-Assisted Chemical Vapor Deposition of Diamond[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2007, 27(08): 1473-1475. |
[9] |
DONG Li-fang1,YIN Yan1,DONG Jian-ming2 . Determination of Net Electric Field in Dielectric Barrier Discharge in N2 by Relative Spectrum Line Intensity [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2005, 25(10): 1727-1729. |
[10] |
DONG Li-fang,YIN Yan. Determination of Mean Electron Energy in O2 Non-Equilibrium Plasma by Relative Spectrum Line Intensity [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2005, 25(09): 1534-1535. |
|
|
|
|