Study On The Motion Of Single Electron In Gaussian Pulse Assisted By Magnetic Field And Its Thomson Scattering

The Thomson scattering generated by the interaction of ultrashort laser with single electron is one of the main generation methods of X-ray.The advantages of the X-ray generated by this method lie in the simple action model,good direction,high brightness and adjustable energy of the X-ray,so it has a broad application prospect in the fields of physics,chemistry,biology and medicine.Most of the previous researches on Thomson phenomenon caused by the interaction between laser and single electron are based on the plane wave laser beam,and the magnetic resonance acceleration mechanism generated by the external magnetic field is seldom considered.This dissertation mainly studies the motion behavior of single electron and its Thomson scattering under Gaussian pulse with longitudinal Gaussian envelope assisted by magnetic field.In the second chapter of this dissertation,based on the Maxwell equations and Lorentz formula,the momentum differential equation of the single electron in the electromagnetic field is derived,and the analytical solutions of the momentum and displacement of the single electron in the magnetic field assisted Gaussian laser pulse are obtained.It is found that the momentum and energy of single electron increase with the increase of laser pulse width when the laser intensity and magnetic field auxiliary parameters are fixed.With the increase of the displacement,it is found that the momentum in the z direction is always positive,which means that the single electron will not move backward when driven by the laser.In the study of the motion of single electron in the magnetic field assisted Gaussian laser pulse,it is found that when the laser pulse width is fixed,the change of the initial phase will significantly affect the motion of single electron,and the effect of the initial phase on the momentum p_x,p_y is far less than the effect of the initial phase on p_z,?;with the increase of the initial phase,the displacement of single electron in all directions is Significantly reduced.At the same time,in the case of different laser pulse width,the smaller the laser pulse width,the more obvious the effect of the initial phase change on the motion behavior.In the third chapter of this dissertation,the Thomson scattering characteristics of a single electron under a magnetic field-assisted Gaussian laser pulse are studied based on the motion solution of the single electron solved in Chapter 2.It is found that with the increase of laser intensity a the scaling law of radiation spectrum proportional to laser intensity is obtained at the same time.At the same time,in the low-frequency radiation spectrum,the radiation peak is mainly concentrated between the laser frequency and the single electron cyclotron frequency.In the high-frequency part of the radiation spectrum,the radiation frequency position corresponding to the radiation spectrum peak is fixed and does not depend on the change of the laser pulse width.In the study of the initial phase,the overall shape of the radiation spectrum remains unchanged with the change of the initial phase,and it is found that the change of the initial phase has no effect on the forward radiation spectrum of the single electron.