共查询到17条相似文献,搜索用时 140 毫秒
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LSO晶体射线荧光图像转换屏性能研究 总被引:1,自引:0,他引:1
理论分析LSO晶体相对ST-401塑料闪烁体的发光效率,并在平均能量为1.25 MeV的γ射线源上进行标定,实验测得20 mm厚度LSO晶体的相对灵敏度是10 mm 厚度ST-401塑料闪烁体的约60倍,实验数据与理论数据相符,同时理论计算了LSO晶体的空间分辨,相对强度降低50%时的线扩散约为0.18 mm,优于ST... 相似文献
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针对高强度脉冲辐射测量中常用的闪烁体探测器,对其直径为50 mm、厚度分别为5、8、10、15、20、25、30、40 mm的ST401塑料闪烁体进行了DD、DT中子灵敏度刻度,并采用Geant4对其相对中子探测效率进行了模拟研究;并由理论计算给出了直径为90 mm、不同厚度闪烁体的相对中子探测效率,厚度为50 mm、不同直径闪烁体的相对中子探测效率。 相似文献
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LSO闪烁晶体探测器能量响应研究 总被引:1,自引:1,他引:1
应用蒙特卡罗与解析计算相结合的方法计算了一种LSO闪烁晶体探测器对不同能量中子和γ射线的相结灵敏度,分析了晶体长度对探测器灵敏度和γ/中分子分辨能力的影响,理论计算的灵敏度能量响应曲线与实验标定结果进行了比较,两者趋势基本一致。 相似文献
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介绍了脉冲X射线在ST401塑料闪烁体上的相对灵敏度标定方法,并在"晨光号"脉冲X射线源和钴辐照源上,实验标定了厚度从1~50 mm的六种规格塑料闪烁体的相对灵敏度,并给出了标定数据的不确定度评定,其标定数据能够作为ST401塑料闪烁体相对灵敏度转换的实验依据. 相似文献
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Moses WW Janecek M Spurrier MA Szupryczynski P Choong WS Melcher CL Andreaco M 《IEEE transactions on nuclear science》2010,57(3):1570-1576
We have explored methods for optimizing the timing resolution of an LSO-based detector module for a single-ring, "demonstration" time-of-flight PET camera. By maximizing the area that couples the scintillator to the PMT and minimizing the average path length that the scintillation photons travel, a single detector timing resolution of 218 ps fwhm is measured, which is considerably better than the ~385 ps fwhm obtained by commercial LSO or LYSO TOF detector modules. We explored different surface treatments (saw-cut, mechanically polished, and chemically etched) and reflector materials (Teflon tape, ESR, Lumirror, Melinex, white epoxy, and white paint), and found that for our geometry, a chemically etched surface had 5% better timing resolution than the saw-cut or mechanically polished surfaces, and while there was little dependence on the timing resolution between the various reflectors, white paint and white epoxy were a few percent better. Adding co-dopants to LSO shortened the decay time from 40 ns to ~30 ns but maintained the same or higher total light output. This increased the initial photoelectron rate and so improved the timing resolution by 15%. Using photomultiplier tubes with higher quantum efficiency (blue sensitivity index of 13.5 rather than 12) improved the timing resolution by an additional 5%. By choosing the optimum surface treatment (chemically etched), reflector (white paint), LSO composition (co-doped), and PMT (13.5 blue sensitivity index), the coincidence timing resolution of our detector module was reduced from 309 ps to 220 ps fwhm. 相似文献
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晶体的不同的表面处理影响着总的光输出量,进而影响有它们构成的PET探测器的性能。为了优化设计一个新提出的深度检出型探测器,比较研究了不同表面情况的LSO晶体组成的该探测器的光输出量和时间分辨率特性。 相似文献
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杨有琏 《核电子学与探测技术》1989,9(3):135-141
本文给出了铑自给能探测器的热中子灵敏度和中子灵敏度的理论计算公式、燃耗修正公式以及不同中子温度下的换算公式。运用这些公式对ZTRh 123型铑自给能探测器的热中子灵敏度和中子灵敏度进行了理论计算,并在反应堆中对其进行了实验验证。其结果表明,理论计算值和实验标定值是相吻合的。其偏差:热中子灵敏度为8.5%,中子灵敏度为3.9%。 相似文献
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介绍了利用K600中子发生器进行Si-PIN探测器灵敏度标定的实验方法,并在实验中测出了Si-PIN探测器对14MeV中子的直照灵敏度。同时,利用MCNP模拟程序对Si-PIN探测器不同能量的中子直照灵敏度进行了理论计算,实验灵敏度处理结果和理论计算值较为一致。 相似文献
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用薄膜~(252)Cf源测定ST451快中子探测器的相对效率 总被引:3,自引:1,他引:3
本文叙述了用飞行时间测量~(262)Cf瞬发裂变中子能谱来刻度ST 451探测器的快中子相对效率响应的方法。在飞行时间谱仪中,一个流气式的微型电离室作为裂变碎块的探测器。文中给出了对实验数据的处理和修正的过程。得到了阈值分别为0.420、0.625、0.825、1.168、1.565和1.882MeV中子能量从几百keV到10MeV范围内的相对探测效率。实验结果与用Monte Carlo方法计算的效率作了比较。 相似文献
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Williams M.B. Sealock R.M. Majewski S. Weisenberger A.G. 《IEEE transactions on nuclear science》1998,45(2):195-205
We are developing a positron emission tomography (PET) detector with depth of interaction (DOI) sensitivity for breast and small animal imaging. The detector uses layers of high density scintillators sandwiched between orthogonal ribbons of wavelength shifting optical fibers. The fibers are coupled to microchannel plate (MCP)-based position sensitive photomultiplier tubes (PSPMTs) containing a crossed delay line readout anode. Preliminary measurements have been made using blue-green waveshifting fiber ribbons coupled to Lu2(SiO4)O:Ce (LSO). The measured photoelectron yield due to wavelength shifted light from the fibers is sufficient to ensure a Poisson probability of only 1.0% that no photoelectron is generated in a given MCP PSPMT. Measurement of internally reflected scintillation light permits energy resolution of better than 25% at 511 keV. Optical fiber readout of high density inorganic crystals provides a significantly larger detective area per unit phototube area than do one-to-one coupling schemes using PSPMTs. With its ability to accurately image single photons, the MCP PSPMT solves problems that have prevented other types of PSPMTs from being used in such a configuration, namely poor resolution at the low light output level of the optical fibers 相似文献
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本文主要介绍了设计携带式环境X,γ照射率仪探头时的考虑,并对能量响应,角响应等几方面作了计算。探头是直径75mm、高82mm的几乎是圆筒形结构的塑料闪烁体,表面喷涂ZnS(Ag)。实验和计算结果基本一致。同时和西德H7201型仪器进行了比对,结果表明,两种仪器性能一致。 相似文献