Research and Implementation of Numerical Simulation of Power Intensity in Neutral Beam Transport Based on QT Framework

The high-energy and stable neutral beam injector is a crucial auxiliary heating equipment for achieving plasma ignition in the tokamak of nuclear fusion devices. During experimental operations of the neutral beam injector, the beam must be extracted as far as possible without aberration through electrode acceleration, beam neutralization, ion deflection, and other processing. However, the inevitable aberration and space charge effects of the beam extraction system cause the beam to continuously diverge during transmission. Therefore, it is necessary to simulate the spatial distribution of beam transmission power based on set parameters before experiments. Thus, the thermal load of internal components of the neutral beam injector is obtained. These data can better guide actual physical experiments. In this paper, the Qt framework and C++ programming language are adopted to design and implement a numerical simulation software for the spatial distribution of neutral beam transmission power. The software has high interactivity and complete functionality, including a proposed model for beam power density deposition and a beam convergence model. The experimental simulation results are visualized using the QCustomPlot class and ECharts software, and the two-dimensional results are optimized based on the quadratic Bezier curve. Highlights of the study include the adoption of a new beam convergence model, the migration of the 3D coordinate transformation model into the beam convergence model through computational programming techniques, which makes the calculation of beam convergence more universal, and the addition of a smoothing function method to optimize simulation results. Through testing, the stability of the software has been demonstrated. This software provides data guidance for actual beam extraction experiments by simulating beam power deposition at different positions, valuate references for the optimization design of the neutral beam injector.