1-D transport code is used to examine the ignition of plasma on the improved confinement mode and impact of profile effect on the burning performance. Energy transport, He-ash particle transport and poloidal magnetic field transport equations are solved with a thermal diffusivity of current diffusive ballooning mode model. The ratio of a thermal diffusivity and a He-ash diffusivity is introduced as a parameter and assumed to be constant. For a fixed current profile, the existence of the ignited state is shown. An internal transport barrier is formed autonomously even if parameters lie in the L-mode boundary condition. It is found that the sensitivity of the ignition condition on the density is strong and there is no margin of ignition for the density limit when density profile is flat. However, if a peaked profile of density is chosen, solutions which satisfy the density limit exist. The long time sustainment of ignition is also shown, solving poloidal magnetic field transport simultaneously. It is shown that the ignition is sustained within the time scale of burn-time, however, MHD stability should be considered in the time scale of current diffusion.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)