Fit of the experimental He I 4922 line spectrum and result of the simulation. The electron temperature has been taken from the Boltzmann-plot of the Si II lines. This line overlaps with the He I 5016 line. The best fit for the He I 4922 line has been found by taking the electron density of the plasma and the relative intensities of both lines as fit parameters. The fit of He I 5016 has not been sought, it arises in a natural way from the value of N_e set by the line 4922. The two spectral lines that appear on the right side of the figure, above the forbidden component of He I 5016, arise from Silicon impurities.