1 - Nuclear Sciences and Applications - IAEA

74 JT-60TEAM
3 :
LIH
*3.1HA
2.8HA
A 2 HA
• 1 HA
DIV(OUTSIDE)
MA
1 HA
OIV(LOHER)
• 1 HA
FIG. 5. (a) Plasma stored energy W versus absorbed heating power Pabs and (b) global energy confinement
time T£ versus P^s.
electron density including its radial profiles. No significant difference in the stored
energy was observed among the different configurations (limiter, outside divertor and
lower single-null divertor) although the lower single-null discharges have a smaller
plasma volume than the other configurations (by 40%).
A simple offset linear relationship, W = Wo + if c Pabs, can be deduced from
the experimental data. The offset value Wo is increased with Ip, while the incremental
energy confinement time, rjf (=AW/APabs), is about 0.054 s; it is likely to be
independent of Ip. The energy confinement time can be estimated from the equation
rE = W/(Pabs - dW/dt). The relationship of TE with Pabs is shown in Fig. 5(b). The
confinement time degrades with Pabs and is improved with Ip. The offset linear
scaling of W yields the relationship TE = if 0 + W0/Pabs at dW/dt = 0. Further
investigations are being carried out on confinement scaling including size effects.