Normalized spatio temporal plots of the (singlet + triplet) metastable sources (a)–(c) and the electron impact excitation rate from the ground state into the He-I (3s)3S1 level (d)–(f), obtained from PIC/MCC simulations for different numbers of consecutive harmonics N (columns). The positions of the sheath edges are shown as solid white lines. The base frequency is = 13.56 MHz, φpp = 500 V, and the N2 admixture concentration is 0.05%.
Experimental data are marked as exp
Simulation data are marked as sim
x [t/TRf] , y[mm]
(Figure5a-5c): sim Metastable source [a. u.]
(Figure5d-5f): sim Exc. Rate [a. u.]
(Figure5a_5d_Sheath to Figure5c_5f_Sheath): sim sheath edges of the plasma. These sheaths are the same for each corresponding metastable source and Exc. rate