Design And Research Of High-efficiency Relativistic Backward Wave Oscillator For Permanent Magnet Packaging

Relativistic backward wave oscillator(RBWO)has great potential for development due to its high efficiency,simple structure and suitable repetition frequency.It has attracted much attention in many high power microwave(HPM)devices.However,the magnetic field system required by the relativistic backward wave oscillator is large in size and high in energy consumption,which greatly limits the process of practicality and miniaturization.This thesis mainly solves the problem of low efficiency of the relativistic backward wave oscillator by guiding the magnetic field,and studies the small radial relativistic backward wave tube.The thesis first conducts theoretical research on the relativistic backward wave tube.It explain the magnetic quantity and magnetic circuit,analyze the repulsive force between the electrons in the RBWO,the electron is constrained by the guiding magnetic field,the electron beam is acted on by the microwave field,and study its motion state,and discuss the degree of influence of these forces on the magnitude of the microwave.The interaction with the gap and the wave equation of the interaction between the electron beam and the microwave are analyzed.The equations satisfied by the electron distribution function and the micro-winding theory in the relativistic backward wave tube are obtained,and the Bessel function is used to simplify,and the relationship between the guided magnetic field and the microwave of the relativistic backward wave tube oscillator is obtained.The magnetic field of RBWO is divided into low magnetic field,high magnetic field and cyclotron resonance region.The thesis studies the RBWO working in the low magnetic field.Subsequently,a particle simulation was used to study the RBWO under low magnetic field.Change the guiding magnetic field,electron beam voltage,and electron beam current to generate microwave height.Adjust the depth of the slowwave structure of the RBWO,observe the microwave change pattern on the oscilloscope,and analyze the statistical data to find the best working state.Based on this,a low magnetic field S-band relativistic backward wave oscillator with a guided magnetic field of 0.24 T,an electron beam pressure of 725.00 KV,a beam current of6.00 KA,a frequency of 3.53 GHz,a microwave power of 1.22 GW,and a beam conversion efficiency of 27% is designed.Provide data basis for the experimental exploration of the RBWO.Finally,the relativistic backward wave oscillator designed in Chapter 3 is experimentally explored on the Marx accelerator platform.When the external magnetic field on the high current electron beam accelerator platform,the electron beam voltage,and the electron beam current.Obtain a microwave output with an average power of 1 GW,a frequency of 3.58 GHz,and a pulse width of 90 ns.The output is a stable and good single pulse,and a repetitive frequency operation experiment of 1 Hz and 20 s is carried out.The experimental conclusion basically demonstrates the simulation results.The designed low magnetic field S-band relativistic backward wave tube meets the requirements,which lays a good foundation for the high-efficiency relativistic backward wave tube for permanent magnet packaging,and it is feasible to realize the miniaturization and practicality of the HPM system.