Design and CFD analysis of hypervapotron-typed ion dump for KSTAR NBI-2 system

•This manuscript presents the design of the ion dump for the KSTAR NBI-2 system and the results of the CFD analysis using Ansys CFX.•The ion dump of the KSTAR NBI-2 has been designed to use a hypervapotron-typed channel to withstand the maximum heat flux of about 6.7 MW/m2.•The surface temperature on the single phase flow condition analysis is lower than one on the sub-cooled boiling condition analysis.•The ion dump of the KSTAR NBI-2 is expected to operate below the allowable temperature because the maximum temperature of the ion dump is about 428.4 °C. The NBI-2 system for the KSTAR has been designed to provide plasma heating and current for maximum 300 s which has the capability of 6 MW of deuterium neutral beam power. The NBI-2 system is under construction on site to be operated for the beam injection into the KSTAR plasma from the 2018 KSTAR campaign. The ion dump modules consist of the full, half, and third energy components is positioned on one side of the bending magnet. The ion dump of KSTAR NBI-2 system is designed with a hypervapotron-typed channel to withstand a heat flux of about 6.7 MW/m2 that was calculated by the beam transfer code simulation. The water flow rate supplied to each hypervapotron channel of the ion dump is about 1.9 kg/s at inlet. The inner size of the hypervapotron channel is modified to reduce a pressure drop and a liquid velocity difference in the channel. The CFD analysis using Ansys CFX is performed to verify its availability in the high heat flux condition. There is no problem to use the ion dump of the KSTAR NBI-2 system because the maximum temperature of the ion dump body made of CuCrZr is about 428.4 °C which is below allowable temperature of 500 °C.