The Generation And Transmission Research Of Intense Relativistic Multiple Electron Beams

Relativistic klystron (RKA) has a very wide range of applications and developmentprospects in terms of high-energy particle accelerators、 high power radars andcommunication systems, but the traditional relativistic klystron is difficult to meet thedemands of increasing power. Multi-beam Relativistic Klystron works in parallel withmultiple low perveance electron beams, it has a higher efficiency、lower operatingvoltage and a higher total beam, therefore, it can meet the demands of increasing power.In china, The Multi-beam Relativistic Klystron is still in its infancy，there is no reportabout the generation and transmission of intense relativistic multiple electron beams.This paper is based on this demand, it researches the generation and transmission of thefan-shaped and circular intense relativistic multiple electron beam, and analyzes thetransmission characteristics, it can provide a reference for the design of intenserelativistic multi-beam klystron.Firstly, this paper researches the generation and transmission of fan-shapedmulti-beam intense relativistic electron beams by CST simulation and experience, andgives the theoretical validation, gets the following conclusions:1. The fan-shaped electron beams are emitted by the corner、outer edges、side edgesof the fan-shaped cathode.2. The addictive effects of self-electric field and induced electric field offan-shaped electron beam make it to rotate around its own center in the transmissionprocess of the electron beam in the hollow drift tube; at the same time, because of theinteraction between the self-electric field in the hollow drift tube, it makes it to rotatearound the system’s center.3. The independent channel of multiple fan-shaped hole drift tube isolates theinteraction between the self-electric field during the transmission process of fan-shapedelectron beams in multiple fan-shaped hole drift tube, it only rotates around its owncenter, not rotating around the system center.Then in view of the fan-shaped electron beam rotating around its own centerduring the transmission process, this paper analyzes the generation and transmission of circular intense relativistic electron beams by CST simulation; and compares the impactof the transmission of the electron beam of the diode region extending into the innerconductor and not projecting into the inner conductor. At the same time, it analyzes theimpact of beam transport of axial magnetic field、the anode voltage and electrodespacing, gets the following conclusions:1. Extending the inner conductor in the diode region can make the electric fielddistribution of cathode to be relatively more uniform，therefore, it can improve thetransmission efficiency of electron beam.2. By changing the anode voltage, electrode spacing can change the beam size,thereby change the space charge effect, thus affect the transmission efficiency ofelectron beam.3. Enhanced axial magnetic field can overcome the diffusion of the beam causedby the beam space charge effect, in turn, can improve transmission efficiency ofelectron beam.