Upgrade of the Neutral Beam Injection System on EAST

The experimental advanced superconducting tokamak (EAST) is one of the fully superconducting tokamaks. A high-power neutral beam injector (NBI) system consisting of two injectors (EAST-NBI) was employed on EAST for plasma heating and current driving. The designed deuterium beam energy is 50-80 keV, beam power is 2-4 MW, and the beam duration is 10-100 s. Each beamline is equipped with two hot cathode ion sources and can be operated individually. In order to support the planned physics research on EAST, the NBI-2 was shifted from port F to port D, and at the same time, its injection direction was changed from counter-injection to co-injection. Furthermore, the high power ion source was optimized with better feedback control for stable long pulse beam, and a new technology of beam re-turn on was also developed and applied aiming at long pulse beam injection. Details of the NBI status will be presented in this article.