A similarity relation and its deviation between two ICRF systems in different tokamaks

The similarity relations between any RF systems in tokamaks for the wave propagation and damping in plasmas were found kinetically by solving the coupled equations between Maxwell’s equation and Fokker-Planck equation [1]. By changing plasma density and pressure, machine geometry (major radius), and RF wave frequency and power according to the similarity rule, there exists a set of solutions that show the consistent change in the background magnetic fields, the wave electric and magnetic fields, and the particle distribution function, which is well verified by the coupled codes (e.g. TORIC or AORSA/CQL3D/ECOM). When there exist some deviations of a part of the similarity scaling (practically in many tokamaks), the impact of the deviations on several important physics are analyzed, especially for ICRF waves [2]. Three new scaling parameters can represent the change of the Doppler effect, the plasma beta, and fast ion kinetic effect between JET and ITER ICRF systems. Using the scaling parameters, one can estimate the ITER optimized minority concentration, the electron damping fraction, and the ion effective temperature based on the existing JET results without numerical simulations, which could be useful for a rough design of experiments.