Development Of An Energy Continuous Tunable Laser Compton Scattering(LCS) Source And Relevant LCS Application

Laser Compton Scattering(LCS)light source can generate high flux,quasi-monochromatic,short-pulse,highly polarized X/γ-rays,and can be miniaturized.These characteristics make it widely used in many fields such as fundamental science,medicine,industry,material and even national security.At present,the experimental study of LCS light source and the related application research have become a worldwide research hotspot.To follow the international trends and meet the demands from domestic users,we proposed to build a high-performance LCS gamma light device on the storage ring of Shanghai Light Source.Two key technical problems arise in the design process of SLEGS: 1.continuously adjusting the laser incident angle in a wide angle range under high vacuum environment;2.keeping the laser pulseand electronbunch overlapped and synchronizedin the magnitude of micrometer and picosecond with arbitrary laser incident angle.In order to solve these two problems,we decided to build a protype of SLEGS,named SINAP-III.New idea and corresponded techniques which may be the potential methods to overcome the key technical problems are tested on the machine.In this dissertation,we first demonstrate the design of SINAP-III facility,and then show the research on two applicationof the produced gamma ray from SINAP-III and other LCS light source.In the part of SINAP-III facility design,we first give a brief review of the design and current status of each subsystem of SINAP-III,and then focus on design process of interaction chamber which is the key component of the whole system.An optical path structure suitable for rotation within vacuum is proposed and optimized according to the expected gamma-ray flux and the constrain of available space.The corresponding devices for adjustment and observation are also designed.The accuracy of maching and installation of each device are also provided.The new interaction chamber can realize wide range(from 20°to 160°),highaccuracy(step size < 0.01°)adjustment of laser incident angle,which would enable convenient control on the maximum energy of the generated X/γ ray.Thisdesigncanbe applied to other LCS sources to expand the available energy range.In the part of LCS gamma-ray application research,we first developped a new consective energy calibration method based on the steep Compton edges of the LCS photons’ energy spectra.This method can realize consecutive energy calibration in the neighborhood of a certain energy which would improve the calibration’s precision in the energy region.It can also achieve direct calibration at high energy region of several MeVs where detectors can only be calibrated by extrapolation in conventional methods.The effects of systematic uncertainties on the accuracy of this calibration method are studied by simulation,using the design parameters of SINAP-III.The results show that SINAP-III device is able to perform energy calibration work over the energy region from 25 keV to 740 keV.The precision of calibration is better than 1.6% in the energy region from 25 keV to 300 keV,and is better than 0.5% in the energy region from 300 keV to 740 keV.Theother LCS gamma-ray application research carried out in this work is computed tomography(CT)using LCS gamma-ray.The experiment is performed on HIGS facility,which is the world’s currently brightest LCS light source.The gamma-ray’s energy is optimized to give maximum contrast resolution.We design the model used for imaging and calculated the appropriate exposure time and perform normalization and correction to the transmitted gammaray intensity distribution recorded by gamma-ray camera.The experimental results show that the spatial resolution of the reconstructed model is better than 1mm(10Lp / cm),and the contrast resolution is better than 0.03mm-1,which can be used for element identification.