Integrated operating realization to achieve 2 MW negative ion beam acceleration on CRAFT NNBI facility

The Comprehensive Research Facility for Fusion Technology (CRAFT) integrates various testing and demonstration facilities aimed at developing critical technologies and components for magnetic confinement fusion reactor. Among them, the CRAFT Negative Ion Source Neutral Beam Injection (CRAFT NNBI) facility has initially been completed. In the third experimental campaign on the CRAFT NNBI facility, negative ion beam acceleration reached a new record: MW-level power was sustained for 120 s with a beam current of 11.7 A at 200.3 keV. The negative ion beam was extracted from the dual-driver radio frequency (RF) negative ion source with a total RF power of 65 kW and cesium (Cs) vapor was injected from the upper and lower lateral walls. These results provide further support for the subsequent experiments on the CRAFT NNBI facility.