Simulations of Neutral Beam Injection in Quasi-Stationary Operation Scenario of T-15MD Tokamak

The influence of refined parameters of the upgraded system for 6-MW-power neutral beam injection into the T-15MD tokamak plasma was analyzed numerically. The efficiency of toroidal current drive in plasma has been determined, and the profiles of absorbed power of the injected neutral beam, the safety factor, and the bootstrap current have been calculated. The possibility of replacing the ohmic current in plasma with the current driven by the upgraded neutral beam injection system has been investigated. The results of calculations performed for neutral beams with monoenergetic distribution and more complicated three-component energy composition are compared. For the first time, for simulating future T-15MD shots with neutral beam injection, the NUBEAM code was used in combination with the ASTRA code. The calculations were performed with allowance for the real geometry of injectors and the parameters of ion sources. The calculation results obtained using the NUBEAM code are compared with the calculation results obtained using the new version of the ASTRA-NBI neutral beam injection module, as well as the BTR code, which optimizes the parameters of neutral beam injection. The calculations show that the fraction of current driven by the upgraded neutral beam injection system was approximately 30%.