The electron number density profiles along the symmetry axis in the time range between 2 and 14 ns calculated using the FEDM code. The data are stored as in form of a table where the first column is z [m] and each subsequent number density of electrons in [m^-3] at different times during the streamer propagation (2, 4, 6, 8, 10, 12, and14 ns).

Dataset 'Figure 7a'
column 1: z [m]
column 2: n_e [m^-3] @ t = 2 ns
column 3: n_e [m^-3] @ t = 4 ns
column 4: n_e [m^-3] @ t = 6 ns
column 5: n_e [m^-3] @ t = 8 ns
column 6: n_e [m^-3] @ t = 10 ns
column 7: n_e [m^-3] @ t = 12 ns
column 8: n_e [m^-3] @ t = 14 ns