Design Of A New Concept Microwave Frequency Control System For Standing-Wave Electron Linac

Electron linear accelerator is an artificial high-tech equipment which accelerate electrons by an electromagnetic field,and the electrons obtain higher energy.Now it's widely used in industry,agriculture,health care,science of nuclear physics and other fields.Microwave auto frequency control system(AFC system)is a very important part of electron linear accelerator,used for keeping the output frequency of the microwave system and accelerating tube operating frequency consistency,and especially indispensable for standing wave accelerator which work on narrow-band.In this paper,firstly,the principles of the existing AFC system be briefly analyzed,and point out the deficiencies and defects of existing systems.And then proposes a new self-optimizing control concept of AFC system aims to enhance anti-jamming capability of the whole microwave system,stability of AFC system,and dynamic performance of control.The dissertation introduces the control principle of the new AFC system,processing and control of the input signal,and hardware and software design of the system.System main circuits includes an analog circuit for pretreat monitoring signals of system,and a digital circuit consist of microcontroller,AD chips,and a drive circuit of magnetron tuner motor.Software written in C,using a modular,top-down design approach,includes phase-locked type and dose rate determination type.Design process integrally using formulas derivation,chart analysis,and Matlab,Multisim,Proteus and other professional software to aid design.Finally,a actual circuit according to the design be made and tried on medical standing wave electron linear accelerator platform for an online debugging and experiments.Experimental results show that the new AFC system can meet the expectation of design,and improve the anti-jamming capability of the microwave system,and in contrast to existing systems the control performance can also be improved.At the end of the paper,some ideas and prospects be put forward for the future work of the AFC system.