THE MATCHING CONDITIONS FOR GUIDED RELATIVISTIC ELECTRON BEAMS IN A DRIFT TUBE

Two guiding methods of continuous relativistic electron beams are presented.They are the axial magnetic guiding and radial electrostatic guiding.In the assumption of the linear force,the analytic formulations of matched beams are obtained for three guiding technologies:the magnetic guiding.electrostatic guiding and mixed guiding of the two technologies.The results indicate that solenoid strength over the mixed guiding region is reduced not linearly but parabolically.when the neutralization fraction is increased linearly to create a constant guiding strength channel over the entire length of the region.Using LGERKB code to simulate transverse motion of V electrons in abeam slice,we have obtained lots of information including envelope and its evolution,r.m.s.emittance.electron trajectories,and phase space distribution of the N,electrons-phase space diagram,etc.In the case of linear force.the simulated and analytic results are in agreement with each other.The envelope osillation is found in transport computation of the unmatched beam.Its wave number is about twice as large as the betatron number of the corresponding matched beam.It must be noticed that the length of mixed guiding region Lm should be as long as possible to keep the axial motion of the beam umattec-ted affecting.Gaussian Unit is used.