Normalized spatio-temporal plots of the electron impact excitation rate from the ground state into the He-I 1s3s 3S1 level (d-f), measured for different peakto-peak voltage amplitudes at N = 4 (“pea
Normalized spatio-temporal plots of the electron impact excitation rate from the ground state of helium into He-I 1s3s 3S1 obtained experimentally for N = 1 (first row) and N = 4 (second row) and fo
Normalized spatio temporal plots of the electron impact excitation rate from the ground state into the He-I 1s3s 3S1 level (d-f), measured for different numbers of consecutive harmonics N (“peaks”-
