The Study Of Steady State Of Neutral Beam Injector And Optimization Design Of The Beam Deflection System

Neutral beam injection heating is the main method for the magnetic confinement nuclear fusion device. Beam deflection system is the core equipment of neutral beam injector to realize the neutral beam, its performance determines the working efficiency and safety of neutral beam injector device. This paper analyzes the beam transmission characteristics in beam deflection system, carry out the physical design of beam transport system; using the Poisson process and ANSYS software, electromagnetic properties and thermodynamic performance were simulated for design research; according to the simulation results, the optimization of the beam deflection system was used. According to the requirement of future development, the physical design of electric steering system is carried out.Firstly, the water cooling structure and magnetic field distribution of EAST-NBI are studied, and the operating safety of the EAST-NBI deflection magnet is studied. After the comprehensive measurement, theoretical calculation and numerical simulation of the deflection magnet, the method to optimize the deflection of the magnet is put forward. The results of the testing results, theoretical calculation and numerical simulation of the deflection of the magnet are quite consistent with each other. At the same time, the EAST-NBI can’t adapt to steady stable operation. Without changing the electromagnetic parameters and geometric structure of the original deflection magnet, the water cooling structure has been changed a little. The theoretical calculation and experimental results show that the modified deflection magnet can meet the needs of the continuous wave operation of the EAST-NBI under the existing beam energy.Secondly, using the software of Poisson process and ANSYS, the structure of the deflection magnets obtained by the physical design is analyzed and simulated. In the design process, theoretical calculation and numerical simulation are combined to improve the optimization design, repeated improvements to optimize the design scheme. In this way, on the one hand to save the design and manufacturing costs, on the other hand to design a good quality of the bending magnet.Thirdly, based on the analysis of physical design and simulation analysis, the development of the deflection magnet is completed, and the performance of the magnet is tested. On the one hand, the performance of the water cooling of deflection magnet coil is tested under steady state operation. The experimental results show that the optimized deflection magnet can meet the requirement of the EAST-NBI under the full parameter stable operation. On the other hand, the electromagnetic performance of the deflection magnet is tested. The experimental results show that the excitation coefficient of the two gaps can meet the design requirements.Finally, the advantages and disadvantages of the residual ion magnetic deflection system are studied. On the basis of theoretical calculation and numerical simulation and experimental measurement, referring to the residual ion electric steering system of neutral beam injector, the EAST-NBI residual ion electric steering system is reported. After a detailed theoretical calculation and discussion, results show that the magnetic deflection system can be replaced by electric steering system. The engineering cost is lower than that of the residual ion magnetic deflection system, and the cooling effect of the cooling water system is better than that of the residual ion magnetic deflection system.