Ghost Imaging With X Rays And Neutrons

Ghost imaging(GI),as an indirect imaging method based on intensity correlation,was conceived in the 1990 s.Due to its excellent features of turbulence-free,superresolution and single-pixel imaging,GI has already been used in many fields such as lidar detection,remote sensing and security checking.Compared with GI in the visible or infrared spectrum,x-ray ghost imaging(XGI)and neutron ghost imaging(NGI)started relatively late,but they signify promising advancements in the fields of damagefree imaging and material science.This dissertation presents the results of research on XGI and NGI during the studies for a Ph D degree,and is organized as below.Chapter 1,which is the introduction,reviews briefly the development of GI and introduces the basic concepts and theoretical derivations,including the theory of coherence and the relationship between intensity correlation and ghost imaging.The second part includes Chapters 2 and 3,which describe the work related to XGI.Traditional x-ray imaging is based on the integration of photon signals with array detectors,which require sufficient contrast and gray tones to produce a good image.However,thanks to the features of super-sensitive single-pixel imaging in XGI,the drawback of high radiation dose can be solved.This part introduces several experimental methods and ideas to realize XGI.Among them,with a sandpaper random modulation scheme,we demonstrated ultra-low dose XGI,revealing its great potential in medical imaging;Then,using a matrix modulation scheme,we realized superresolution x-ray imaging with a single-pixel detector,which is a further step forward towards practical XGI.Finally,by implementing a single-pixel spectrometer,we realized energy-selective XGI,which will greatly extend the potential applications of the technology.The third part includes Chapter 4,which is the work related to NGI.In this part,the methodology of NGI is introduced in detail.By fabricating a neutron amplitude modulation mask and combining with time-of-flight techniques,we successfully obtained neutron images of high spatial and spectral resolution with a spallation neutron source,and further verified the feasibility of NGI under low illumination.The scheme is simple in layout and greatly reduces the requirement of strong intensity in high resolution neutron imaging,which is of great significance for promoting the development of the whole field of neutron imaging.The fourth part,Chapter 5,describes the construction of a laser driven pulsed xray source,which is essential as a stable and reliable pulse source for practical XGI and NGI.The chapter starts with the basic physical process in the production of such a source,discusses some basic problems involved in the construction process,then gives some corresponding solutions.At the end,we describe a proof-of-principle demonstration of phase contrast imaging and diffraction using our laser driven pulsed x-ray source,which can be employed for performing XGI in the future.The last chapter is a summary of the key points of each chapter,and highlights the scientific significance and prospective applications of the work.