The Long-distance And Stable Transport Of Relativistic Electron Beams

Space active experiments are experiments that deliberately perturb the space environment in ways that can yield new information about the environment.They offer unique ways to gather scientific information,to study the interaction between space platforms and the space environment,and to perform space engineering.In the study of such problems,the long-distance stable transport of the relativistic electron beam in this environment is of great importance,and it can be well used in spatial detection and earth’s magnetic field structure analysis.This paper mainly studies the long-distance stable transport of the relativistic electron beam in the ionosphere.The main research contents are as follows:Firstly,we use the paraxial envelope model of beam propagation to study the longdistance stable transport of the relativistic electron beam in the atmospheric environment.Studies have shown that the transport of the relativistic electron beam in the atmosphere is obviously constrained by the geomagnetic field.This is mainly due to the electron cyclotron motion along the direction of the magnetic field and travel in the direction of the magnetic field in the form of a spiral.The beam divergence and energy loss resulting from collision effects are key factors affecting the transport in the atmospheric environment.Secondly,a method to keep the stable transport of a relativistic electron beam(REB)in plasmas is proposed and studied by full three-dimensional particle-in-cell simulations.Theoretical analysis shows that the beam transport is mainly influenced by three transverse instabilities,where the excitation of self-modulation instability,and the suppression of the filamentation instability and the hosing instability are of great importance to realize the behaviors of the beam stable transport.By modulating the beam transport parameters such as the electron density ratio,the relativistic Lorentz factor,the beam envelopes and the density profiles,the energy loss is reduced significantly during a 60 m length transport,due to the fact of that the filamentation instability and the hosing instability are inhibited,and the self-modulation instability is utilized effectively.Thirdly,The influence of the magnetic field on the stable transport performance of relativistic electron beams is investigated by two-dimensional particle-in-cell simulation.In this chapter,we firstly studied the influence of the geomagnetic field on the relativistic electron beam transport behavior.The results show that regardless of the atmospheric or plasma environment,the magnetic field will bias the electron beam,beam envelope divergence in the particle-in-cell simulation is weaker than the paraxial envelope model,which may mean that the beam envelope divergence caused by collision divergence is more obvious than the instability; Secondly,we studied the behavior of relativistic electron beam string in the geomagnetic field,which show that affected by self-modulation instability,the relativistic electron beam front beam will affect the transport of the rear beam,so keeping the electron beam with sufficient spacing is more conducive to electron beam string transport; Finally,we explored the anti-magnetic transport method of the relativistic electron beam,and the result show that adding a high-intensive axial magnetic field can exert a good constraint on the electron beam and ensure stable long distance transport,which has the ability to resist the deflection caused by the geomagnetic field.