Abstract. Properties of the toroidal momentum diffusivity (χ) 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/χ_i ~ 0.7–3 at the half radius (r/a = 0.5). The inward convection velocity (−V_conv) increases with increasing χ, and −V_conv/χ ~ 0.5–2 (m⁻¹) at r/a = 0.5. It is found that the ratio χ/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 at r/a = 0.4, 0.5 and 0.6 increases with increasing ion and electron temperatures or temperature gradients.

PACS numbers: 52.25.Fi, 52.30.−q, 52.55.Fa

Print publication: Issue 11 (November 2009)
Received 28 May 2009, accepted for publication 5 October 2009
Published 21 October 2009