Particle Distribution Of The Vacuum Of Space For NBI Of High Current And High Power In The Steady-state Operation Mode

High-energy neutral beam injection (Neutral beam injection, NBI) is one of four tokamak auxiliary heating methods (neutral beam injection, lower hybrid, ion cyclotron waves paragraph, section electron cyclotron waves). Due to the highest heating efficiency, the clearly physical mechanism, it is regarded as the most effective heating method by international fusion community.In this thesis, the composition of gas sources were analyzed with reference to EAST-NBI working principle, fundamental structure and a simplified model of gas supplying system,. The physical models of EAST-NBI and the mathematical equation of the plane crash, as well as the mathematical models of the gas particles in the vacuum chamber based on M-C method, were constructed.On basis of the air sources analysis, the M-C models were calculated with the Matlab software. Spatial distribution of particles in the vacuum chamber and the curves of average pressure in the three main vacuum chamber were obtained. Compared with the experimental data of the EAST-NBI system and the experimental results of the similar foreign equipment, the theoretical models were reliable and practical, which could meet the EAST-NBI vacuum performance requirements.According to the design requirements of EAST-NBI, the steady operation requirements and the latest research results of international fusion community, the overall structure of NBI were designed based on the above simulation results, which is useful for the engineering guidance of EAST-NBI.