一种新型X射线相衬成像实验室系统

目前的X射线相衬成像研究大都采用同步辐射光源。光源点尺寸达微米量级的X射线管辐射具有较好的空间相干性，也可用于相衬成像研究。本文报道了一种基于纳聚焦x射线管的新型相衬成像实验室系统，光源点尺寸可达500nm。实验结果表明，该系统可对低Z样品如生物软组织、有机样品等的内部结构成清晰像，分辨率可达微米量级。与已有系统相比较，其空间分辨率和有效通量都有相当大的提高。锥形光束张角约为300，通过纵向扫描机构调节样品与光源点间距可调整投影放大率，从而降低对探测器分辨率的要求。适用于大样品研究，且可实现样品的横向二维扫描。在医学、生物学、材料科学及化学反应动力学等领域有重要应用前景。

A new type of laboratory system for X-ray phase-contrast imaging

Up to now, X-rays used for the phase-contrast imaging mostly come from synchrotron radiation facility. Radiation from X-ray tubes with a source size of the order of micrometer is also applicable for X-ray phase-contrast imaging (XPCI), because of its fairly good spatial coherence. In this paper, a new type of laboratory system for XPCI, based on a nanofocus X-ray tube with the source size of 500 run, is reported. The experimental results show that this XPCI lab system is applicable to the high resolution imaging of the inner structure for low Z samples, such as soft tissues, organic materials etc.. Resolution of a few micrometers was achieved. Compared to the system reported earlier, spatial resolution and effective flux for the new one have been greatly improved. Open angle for the cone-shaped X-ray beam is about 30? Distance between the sample and source can be easily adjusted to meet the specified magnification ratio through projection, so that the limits to the resolution of X-ray detectors can be reduced. It is possible for the system to investigate the samples with relatively large size, while a mechanic system is designed to ensure the transverse 2-d scanning of them. Important application potentials for the XPCI lab system can be found in the fields of clinical medicine, biology, material science, chemical reaction dynamics, etc..