Measurement of Atomic Number by MV X-Ray Scattering Spectra Analysis
Measurement of Atomic Number by MV X-Ray Scattering Spectra Analysis
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DOI：
10.1109/tns.2012.2228882
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发表时间：
2013-01
影响因子：
1.8
通讯作者：
Weiqi Huang;Yigang Yang;Yuanjing Li
中科院分区：
文献类型：
--
作者：
Weiqi Huang;Yigang Yang;Yuanjing Li
为了测量材料的原子序数Z，本文提出了一种基于MV X射线散射谱分析的Z鉴别方法。散射光子是X射线与物质相互作用产生的，携带Z信息，包括正电子湮没光子、韧致辐射光子和康普顿散射光子。利用LaBr3（Ce）探测器的分辨时间短（<100 ns），在5 μs的X射线脉冲宽度内测量散射光子，以解决脉冲堆积问题。采用120 MHz高采样率、14 bit高分辨率的ADC对LaBr3（Ce）探测器采样后的信号波形进行数字化处理。设计了一种离线重建散射光谱的算法。设置适当的屏蔽结构，以减少来自加速器目标的透射光子和环境中散射光子进入探测器的数量。这些设计确保在强脉冲辐射场中有效地获取散射光子。我们研究了Z从13到82的10种材料。初步的实验结果表明，该方法可以成功地测定不同材料的Z值。
In order to measure atomic number (Z) of materials, we present a Z identification method based on MV X-ray scattering spectra analysis in this paper. Scattering photons, which include positron annihilation photons, bremsstrahlung photons and Compton scattered photons, are generated by interactions of X-rays with matters and carry their Z information. A LaBr3(Ce) detector is used for its short resolving time (<; 100 ns) to measure scattered photons to alleviate pulse pileup problem in the 5 μs X-ray pulse duration. ADC with high sampling rate of 120 MHz and high resolution of 14-bit is used to digitize signal waveform from the preamplifier of the LaBr3(Ce) detector. An offline algorithm is designed to reconstruct scattering spectra. Appropriate shielding structure is set up to reduce the number of transmission photons from accelerator target and scattering photons in environment that enter the detector. These designs ensure effective acquisition of scattering photons in the intense pulsed radiation field. We investigated 10 materials with Z from 13 to 82. Preliminary experimental results show that Z of different materials can be determined successfully.