Characteristics of momentum transport in JT-60U H-mode plasmas

摘要

Properties of the toroidal momentum diffusivity (x_φ) and the convection velocity (V_(conv)) in JT-60U H-mode plasmas have been obtained by plasma parameter scans such as the plasma current, neutral beam heating power and electron density. The toroidal momentum diffusivity increases with increasing heat diffusivity (χ_i) over a wide range of radii (r/a = 0.2-0.6) and χ_φ/χ_i ～ 0.7-3 at the half radius (r/a = 0.5). The inward convection velocity (- V_(conv)) increases with increasing χ_φ, and -V_(conv)/χ_φ ～ 0.5-2 (m~(-1)) at r/a = 0.5. It is found that the ratio χ_φ/χ_i increases with increasing ion temperature and decreases with increasing electron density. These tendencies are observed in other radial positions of r/a = 0.3, 0.4 and 0.6. Moreover, the ratio - V_(conv)/χ_φ at r/a = 0.4, 0.5 and 0.6 increases with increasing ion and electron temperatures or temperature gradients.