Abstract
It is essential to understand the physical mechanisms determining the plasma rotation velocity profile for achieving steady state operations in a fusion reactor. Physical mechanisms related to plasma rotation velocity profiles have been investigated through transient transport analysis in the JT-60U tokamak device. Main results are as follows: (i) Fast ion losses due to the magnetic field ripple induce the plasma rotation as a momentum source in the peripheral region of plasma; (ii) The momentum diffusivity and the convection velocity are evaluated from the transient transport analysis using the momentum source induced by the fast ion losses; (iii) Correlations between the momentum diffusivity, the convection velocity, and the ion thermal diffusivity have been found; (iv) Parameter dependences of the momentum transport coefficients (the momentum diffusivity and the convection velocity) have been identified; (v) The measured plasma rotation profiles are almost reproduced through the momentum diffusivity and the convection velocity with a small ion pressure gradient; (vi) Intrinsic rotation, which is not determined by the momentum transport coefficients and the external momentum input has been observed with a large ion pressure gradient. Also another type of the intrinsic rotation, which is driven by electron cyclotron resonance heating, has been identified.
