A free-air ionization chamber in low-energy X-ray has been designed and manufactured at the National Institute of Metrology （NIM, China） according to the defination of air-kerma. The results of a preliminary test sh...A free-air ionization chamber in low-energy X-ray has been designed and manufactured at the National Institute of Metrology （NIM, China） according to the defination of air-kerma. The results of a preliminary test show that the leakage current of ionization chamber is around 2×10^-15A, and the correction factor of ion recombination for the ionization chamber is also obtained. The free-air ionization chamber is suitable for the primary standard in low-energy X-rays.展开更多
Based on the needs of detection and calibration with low-energy X-ray, we used the relationship characteristics of X-ray fluorescence, absorption and limit potential target excitation, developed the X-ray device with ...Based on the needs of detection and calibration with low-energy X-ray, we used the relationship characteristics of X-ray fluorescence, absorption and limit potential target excitation, developed the X-ray device with adjustable intensity (single photon to 107/s), optional energy points (4 keV - 20 keV), highly portable (≤1 kg), by the matching design of fluorescence energy conversion target and modulation means, coupled transport simulation of electron-photon in target, meanwhile, we solved the low-energy X-ray radiation field diagnose problems with HPGe detector, which calibrated with combined technique, including relatively wide energy efficiency simulation and single energy point of absolute efficiency calibration. In single-photon calibration field of soft X-ray pulsar navigation detect, the portable reference single energy radiation fields was applied effectively and got good result, the reference radiation fields provided perfect experiment means for the scientific study of pulsar navigation detecting, sun X-ray monitoring, etc.展开更多
搭建了基于SEM(Scanning Electron Microscope)的多靶材X射线显微成像系统,并对其成像原理进行了分析,改装后的X射线显微成像系统可以通过切换靶材来实现对低能X射线的能量调节,进而实现对轻质样品不同区域的高分辨率、高对比度成像;在...搭建了基于SEM(Scanning Electron Microscope)的多靶材X射线显微成像系统,并对其成像原理进行了分析,改装后的X射线显微成像系统可以通过切换靶材来实现对低能X射线的能量调节,进而实现对轻质样品不同区域的高分辨率、高对比度成像;在现有的平台上,分别使用铝、铬、钨3种靶材对杨树叶和蚂蚁样品进行了DR(Digital Radiography)成像实验,并且对几种靶材的DR成像结果进行了分析.结果表明:使用铝靶材对样品的轻薄(~100μm)、边界区域进行成像,容易获得较好的对比度;而铬、钨靶材则可以在样品较厚(小于1 mm)时获得较好的衬度.展开更多
文摘A free-air ionization chamber in low-energy X-ray has been designed and manufactured at the National Institute of Metrology （NIM, China） according to the defination of air-kerma. The results of a preliminary test show that the leakage current of ionization chamber is around 2×10^-15A, and the correction factor of ion recombination for the ionization chamber is also obtained. The free-air ionization chamber is suitable for the primary standard in low-energy X-rays.
文摘Based on the needs of detection and calibration with low-energy X-ray, we used the relationship characteristics of X-ray fluorescence, absorption and limit potential target excitation, developed the X-ray device with adjustable intensity (single photon to 107/s), optional energy points (4 keV - 20 keV), highly portable (≤1 kg), by the matching design of fluorescence energy conversion target and modulation means, coupled transport simulation of electron-photon in target, meanwhile, we solved the low-energy X-ray radiation field diagnose problems with HPGe detector, which calibrated with combined technique, including relatively wide energy efficiency simulation and single energy point of absolute efficiency calibration. In single-photon calibration field of soft X-ray pulsar navigation detect, the portable reference single energy radiation fields was applied effectively and got good result, the reference radiation fields provided perfect experiment means for the scientific study of pulsar navigation detecting, sun X-ray monitoring, etc.
文摘搭建了基于SEM(Scanning Electron Microscope)的多靶材X射线显微成像系统,并对其成像原理进行了分析,改装后的X射线显微成像系统可以通过切换靶材来实现对低能X射线的能量调节,进而实现对轻质样品不同区域的高分辨率、高对比度成像;在现有的平台上,分别使用铝、铬、钨3种靶材对杨树叶和蚂蚁样品进行了DR(Digital Radiography)成像实验,并且对几种靶材的DR成像结果进行了分析.结果表明:使用铝靶材对样品的轻薄(~100μm)、边界区域进行成像,容易获得较好的对比度;而铬、钨靶材则可以在样品较厚(小于1 mm)时获得较好的衬度.
