Speaker
Description
The neutral beam injection (NBI) system commissioning and first beam heating experiments in Versatile Experiment Spherical Torus (VEST) have been carried out. The ion beam power of ~0.6MW was successfully extracted from the ion source through commissioning. The ion source consists of arc plasma source and multi-aperture accelerator assembly which is developed by Korea Atomic Energy Research Institute (KAERI). The KAERI accelerator system was designed to deliver a 0.6MW with beam energy of 15kV. The arc plasma source can make high power of ~60kW Arc plasmas, which is enough for beam current of ~40A in this accelerator system. By using this NB system, a hydrogen NB power of up to 0.6MW was successfully injected to the VEST plasma. Difference of the plasma parameters by NB injection such as ion temperature, rotation, and plasma density was measured by using thomson scattering system, passive emission spectroscopy and so on. From these experiment results, neutral beam injection efficiency will be discussed in comparison with those of the NUBEAM simulation.
