Latest progress of development of the neutral beam injection heating system on HL-2M Tokamak

In order to carry out the physical experiment of magnetic confinement core combustion plasma, the HL-2M device under construction is intended to construct three 5 MW neutral beam injection heating lines. This paper briefly outlines the overall planning of the neutral beam injection (NBI) heating system of the HL-2M device, the design of the first 5MW-NBI heating beam line, the ion source commissioning experiment, the installation and test results of the injector core components. Through debugging, for single ion source the extraction beam current reaches 36 A, the acceleration voltage is 75 kV, the ion beam power reaches 2.4 MW, and the pulse width is 3 s. It is found by testing that the convergence angle error of 4 ion beam from the injector is less than +0.1°, the deviation between the test values and simulation values of magnetic field with deflecting magnet for deflecting residual ions is less than ±5%, and the static vacuum value of the injector reached 1.0×10^-3 Pa. The injector has adopted a large non-standard cryogenic pump with a pumping speed of 2.4×10⁶ L·s^-1. The trial assembly and test results of the first 5MW-NBI heating beam show that the beam line can meet the technical requirements of NBI heating on HL-2M device.