Effect of negative triangularity on the bulk ions co-current rotation caused by the ion orbit loss at the edge of the tokamak plasmas

The ion orbit loss (IOL) can drive the bulk ions co-current rotation at the edge of the tokamak plasmas. The effect of triangularity on the IOL is investigated by using an analytical tokamak equilibrium model for the shaped plasmas. The peaking speed of the bulk ions co-current rotation at the tokamak edge will be increased greatly with the negative triangularity.