Beam Emittance Measurement Of Lanzhou High Energy Electron Experimental Platform And High Energy Electron Radiography Experimental Research

High Energy Electron Radiography(HEER)has been proposed as a new material diagnostic technology in recent years.The main features of this technology are the strong penetrating power,high space-time resolution,and large area density diagnostic range.Therefore,it is considered as one of the effective diagnostic methods in the field of high energy density material diagnosis.For further research on high energy electron radiography technology,the Institute of Modern Physics,Chinese Academy of Sciences has built an experimental platform dedicated to the research of HEER which is mainly composed of a 50 MeV electron linear accelerator based on a thermionic cathode RF gun,and a set of quadrupole magnet systems.The main work of this paper is to complete the preliminary experimental research of high energy electron radiography by optimizing the beam quality.In order to complete high resolution radiography experiments,we optimized the beam quality firstly.The quality of the electron beam directly determines the accuracy of the HEER,and the beam emittance is an important physical parameter to describe the quality of the beam.Therefore,a set of experimental devices based on the quadrupole scan method is designed to measure the beam emittance,mainly using a YAG screen and a CCD camera to get beam profiles,and a GUI code is written to realizing the image processing and emittance calculation.With the characteristics of convenient measurement,fast and reliable calculation,this measurement provides the basis for subsequent high energy electron radiography experiments.Another important work of the thesis is the experimental research of high energy electron radiography technology.Relying on the high energy electron radiography experiment platform of the the Institute of Modern Physics,Chinese Academy of Sciences,We conducted the first round of high-energy electronic imaging experimentswe designed a special radiography beamline based on the experimental platform and carried out the high energy electron radiography experiment.We optimized and adjusted the accelerator to obtain the electron beam with energy of50 MeV,and completed the radiography experiment with magnification of 1:-2.84 and1:-10.18.First we calculated the resolution based on the radiography results of the TEM grid,the spatial resolution reached below 1 micron for the first time,reaching the international leading level.Then we performed a radiography experiment with theLOGO target.The LOGO sample is a silicon plate with thickness of 170 microns and the lettering depth of 50 microns.The experimental results are good and the image is clearly.This experiment provided experience for subsequent higher resolution radiography experiments,and verified the feasibility of high energy electron radiography technology as a material diagnosis technology again.