Confinement degradation with beta for ELMyH-mode plasmas in JT-60U tokamak

The degradation of energy confinement with increased toroidal beta βT was shown by non-dimensional analysis in JT-60U. The dependence of the energy confinement on βT was examined by both the JT-60U ELMy H-mode confinement database and the dedicated experiment on a single βT scan while and ν* were kept fixed as well as the other magnetic geometrical parameters. In both cases, the degradation of energy confinement with increasing βT was observed, satisfying the relation of . This dependence is a little weaker than that predicted by the IPB98(y, 2) scaling. The fusion power production rate was estimated to increase in proportion to .