Investigation of key parameters for the development of reliable ITER baseline operation scenarios using CORSICA

ITER will demonstrate the feasibility of burning plasma operation by operating DT plasmas in the ELMy H-mode regime with a high ratio of fusion power gain Q ∼ 10. 15 MA ITER baseline operation scenario has been studied using CORSICA, focusing on the entry to burn, flat-top burning plasma operation and exit from burn. The burning plasma operation for about 400 s of the current flat-top was achieved in H-mode within the various engineering constraints imposed by the poloidal field coil and power supply systems. The target fusion gain (Q ∼ 10) was achievable in the 15 MA ITER baseline operation with a moderate amount of the total auxiliary heating power (∼50 MW). It has been observed that the tungsten (W) concentration needs to be maintained low level (n _w/n _e up to the order of 1.0 × 10^-5) to avoid the radiative collapse and uncontrolled early termination of the discharge. The dynamic evolution of the density can modify the H-mode access unless the applied auxiliary heating power is significantly higher than the H-mode threshold power. Several qualitative sensitivity studies have been performed to provide guidance for further optimizing the plasma operation and performance. Increasing the density profile peaking factor was quite effective in increasing the alpha particle self-heating power and fusion power multiplication factor. Varying the combination of auxiliary heating power has shown that the fusion power multiplication factor can be reduced along with the increase in the total auxiliary heating power. As the 15 MA ITER baseline operation scenario requires full capacity of the coil and power supply systems, the operation window for H-mode access and shape modification was narrow. The updated ITER baseline operation scenarios developed in this work will become a basis for further optimization studies necessary along with the improvement in understanding the burning plasma physics.