Design Of The Pulse Power Supply For Acceleration Tube In The Magnetron System

The magnetron is a very important part of the medical electron linear accelerator.The acceleration tube is the core component of magnetron in the electron linear accelerator,and it needs a stable and controllable pulse DC high-voltage,it can ensure the beam emission output stably in the electron linear accelerator.In this design,an improved Marx generator is used as the main circuit to design the pulse power supply for the acceleration tube,which is composed of a pulse charging circuit,a control circuit and its driving circuit.In the design of the charging circuit,the LCC high-frequency series-parallel resonant converter circuit is selected,which is highly efficient and capable of maintaining a soft-switching state during the switching process.Firstly,the different operating modes and operating characteristics of the LCC high-frequency series-parallel resonant converter circuit are analyzed,and then on this basis,the mathematical model corresponding to the LCC resonant converter circuit is established,so as to further elaborate the characteristics of the LCC resonant circuit.The MOSFET driving circuit and its control circuit in the charging circuit are also designed,the component parameters are analyzed and calculated,and the LCC high-frequency series-parallel resonant converter circuit is verified by Or CAD Pspice simulation.In the design of high-voltage pulse generation circuits,the MOSFET used as the switch,its gate drive circuits that must meet both switching synchronization and different high-voltage isolation requirements for each stage of the circuit.Generally,Marx generators need drivers at each stage,it leads to high cost and complex and bulky circuits for these solutions.Therefore,the conventional Marx generator is improved and an all-solid-state Marx generator with a single-gate drive structure is designed.The operating process of the all-solid-state Marx generator is analyzed in detail,and the electromagnetic field is simulated under Ansoft Maxwell software to study the distributed capacitance values in the circuit;and the most suitable component parameters are derived by simulation and debugging under Or CAD Pspice.Combined with Altium Designer and Ansoft Designer,the EMC performance issues in the PCB are simulated and analyzed,and the PCB structure is optimized.The control circuit and driver circuit are also designed.Finally,a prototype is made and the experimental data after testing show that the power supply system is reasonably designed with an output voltage amplitude of 10 k V,peak output current of 1A,repetition frequency of 250 Hz,and pulse width of 6μs.