反散射数字辐射成像系统

反散射成像法是数字辐射成像的主要方法之一，介绍了获得反散射数字图像的实验装置，并着重分析了针对此装置获得的反散性图像的处理方法。     

Development of a fast neutron radiography converter using wavelength-shifting fibers

A fluorescent converter for fast neutron radiography (FNR) comprising a scintillator and hydrogen-rich resin has been developed and applied to electronic imaging. The rate of the reaction between fast neutrons and the converter is increased by thickening the converter, but its opaqueness attenuates emitted light photons before they reach its surface. To improve the luminosity of a fluorescent converter for FNR, a novel type of converter was designed in which wavelength-shifting fibers were adopted to transport radiated light to the observation end face. The performance of the converter was compared with that of a polypropylene-based fluorescent converter in an experiment conducted at the fast-neutron-source reactor YAYOI in the University of Tokyo.     

X射线透射成像技术原位追踪混凝土吸水过程

为了表征二维混凝土的传输过程,制备厚度为1 mm的混凝土薄片. 采用X射线透射成像（TXR）技术,联合扫描电镜、背散射和能谱分析技术（SEM/BSE/EDS）原位追踪水在2维混凝土薄片中的毛细自吸过程. 测试不同质量分数CsCl溶液对X射线透射图像的增强效果. 结果表明,CsCl能够提高吸水过程中混凝土薄片的TXR图像对比度,使得水在混凝土中的渗流路径更清晰、可辨. 水泥浆体在吸收CsCl后,扫描电子背散射图像的对比度显著增强. 不同位置铯原子的EDS能谱结果验证了TXR技术确定吸水前锋位置的准确性.     

High resolution X-ray phase contrast synchrotron imaging of normal and ligation damaged rat sciatic nerves

This study was performed to apply synchrotron radiation (SR) imaging to a neuropathologic evaluation technique after treatment of peripheral nerve blocks. A phase contrast synchrotron images of normal and ligation damaged rat sciatic nerve were obtained with an 8 KeV monochromatic beam and 20-mum thick CsI(TI) scintillation crystal. The visual image was magnified using a 20x microscope objective and captured using an analog CCD camera. Obtained images were compared with conventional light microscopic findings from the same nerve samples. By using an edge enhancement effect of phase const with SR, we could easily discriminate each nerve fiber and identify the arrangement of nerve fibers within a whole thickness (about 1 mm in diameter) of peripheral nerve without sectioning and fixation. The composite SR image of a ligation damaged rat sciatic nerve sample showed that the response to nerve injury was different on each side of the site of injury. The SR image of damaged distal lesion showed destruction of neural microarchitecture and typical extensive Wallerian degeneration of nerve fibers as clearly as histologic image. We could get very detailed morphologic data for Wallerian degeneration of nerve fibers by using the SR imaging technique. We believe that the phase contrast synchrotron imaging has great potential as an imaging tool in the bioscience and medical science.     

快中子照相CCD成像系统反射镜组件设计

基于反射镜组件的刚度、强度和热尺寸稳定性,采用背部4点支撑方案设计了反射镜组件。对反射镜组件进行的静、动态刚度及热尺寸稳定性分析结果表明,反射镜在重力载荷和4℃温升载荷及温度和重力耦合变形下,面形精度达到PV≤λ/10,RMS≤λ/50(λ=400nm)。模态分析结果证明该结构有足够的动态刚度。     

数字辐射成像处理过程的可视化研究

根据数字辐射成像的特点，提出了处理过程可视化的方法，并设计了可视化工具RDIvision，给出了使用该工具的具体例子。该实例表明，通过实现处理过程的可视化，可以更直观地设计算法，更有效评估算法的细节特性。     

我国医学影像技术近十年发展概述

本文综述了我国近十年医学影像技术的发展概况，主要阐述了一些新的医学成像技术系统和设备在我国的开发研究和应用，如：数字成像，包括计算机放射照相CR，直接数字放射照相DR，数字减影血管造影DSA等；计算机断层放射照相CT，包括多种照相技术，如三维重建、CT仿真内窥镜成像CTVE等；核磁共振成像MRI；图像存档与通讯系统PACS等等。     

中子照相技术及其应用

本文简述中子照相的原理、方法和特征。包括中子源 ,中子转换屏 ,中子成像技术等关键技术。给出在 4 5MV静电加速器上快中子照相的结果。并概述中子照相技术的一些应用实例     

小型源热中子照相装置准直慢化系统设计

小型中子源中子照相技术具有便携性强,应用范围广的优点,在检测一些较大或难以移动的样品时较固定式(反应堆中子源)中子照相系统具有优势.采用MCNP软件对一小型中子源中子照相装置的热中子准直屏蔽系统进行了理论设计,确定中子慢化体由238U和聚乙烯构成,辅以石墨反射层和硼聚乙烯吸收层,经优化计算,预计成像处热注量率达104 ...     

高能电子成像研究进展

本文通过蒙特卡罗程序EGS模拟研究了电子束与靶的相互作用,对成像束流光学进行了设计,并对束流匹配对空间分辨的影响、超快分束技术和产生横向均匀束技术等进行了模拟研究。实验验证了高能电子成像能达到μm量级的空间分辨,并可实现厚度、密度分辨及明-暗场成像等特点。同时给出了后续实验及研究计划,希望进一步提高高能电子成像性能并拓宽其应用领域。