Study of the effects of ECH power and pulse length on preionization in the KSTAR Tokamak

In this paper, we present the results of a study of the preionization effects for the Korean Superconducting Tokamak Advanced Research (KSTAR) tokamak (R₀=1.8 m, a=0.5 m, κ=2, δ=0.8, B_T=3.5 T, I_p=2 MA, T_pulse=300 s) that is under construction by the Korea Basic Science Institute (KBSI). The preionization will be given by the Electron Cyclotron Heating (ECH) System with an 84-GHz 500-kW gyrotron tube being made by Communications and Power Industries. The ECH preionization effects are investigated by a 0-dimensional code (TECHP0D) that includes the operational scenarios of KSTAR tokamak. The code is now improved and advanced with carbon, oxygen, and iron impurity effects, and with the self and mutual inductances of seven pairs of superconducting poloidal coils for the KSTAR tokamak.