The Focusing Characteristics Of Capillary And Its Applications On The Fluorescence Imaging And Full-field X-ray Nano-imaging

By using the principle of total reflection,the X-ray capillary can change the direction of propagation.The X-ray can be adjusted and focused.The luminous flux density of the focusing spot can be improved.The advantage of the capillary is that it can realize wide band transmission,wide angle(3600)transmission,a simple structure and low cost.The X-ray transmission efficiency is also high,generally higher than 90%.Because the optical channel number is different,the capillary can be divided into monocapillary and polycapillary channels.The monocapillary has the advantages of a small focal spot,high gain,and a small volume.The polycapillary is composed of a group of hollow glass fiber tubes,and the cross section of the capillary is arranged on six sides.The polycapillary has a high X-ray utilization.However,the focal spot is larger than that of the monocapillary.The different characteristics of capillaries can be applied to the study of fluorescence imaging and nano imaging.The use of a monocapillary small focal spot and fluorescence imaging can improve the imaging resolution and sensitivity of fluorescence.The monocapillary can be used as the secondary focusing element to provide a uniform focal spot that is matched with the imaging zone plate.Because of the high utilization rate of the X-ray,the polycapillary can be applied to the fluorescence imaging of the X-ray tube with low luminous flux.We can make the medium resolution fluorescence imaging with a polycapillary.This thesis is dedicated to the X-ray Imaging and Biomedical Application beamline of Shanghai Synchrotron Radiation Facility(SSRF).The focusing characteristics of the capillary and its application to the fluorescence imaging and full-field X-ray nano-imaging were studied as follows:1.The focusing properties of the monocapillary and polycapillary were researched.The focal depth and focal spot of different capillaries were researched.Then,we researched the effect of fluorescence imaging with nano-imaging.2.The X-ray fluorescence imaging system based on polycapillary technology was established.The fluorescence scanning imaging of the sample and the fluorescence CT imaging of the iodine solution were achieved.The detection element concentration of sample was approximately 1000 ppm.The CT algorithms were simulated and compared.Finally,the MLEM algorithm had a high signal to noise ratio,and a fast reconstruction speed was selected.It has also proven to be faster and reliable in reconstruction by computer simulation and test samples.3.Driven by user requirements,a dedicated full-field X-ray nano-imaging system was designed and constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This microscope is based on a beam shaper and a zone plate,with the optimized working energy range set to 8-10 keV.The experimental test results by a Siemens star pattern demonstrated that spatial resolution of 100 nm was achieved,while the FOV of 50?m is obtained.