Profiles of the He I 4471.5- and 4922-Å Lines in a dc Arc

Measurements were made of the profiles of the He I 4471.5- and 4922-Å lines in a dc arc for electron densities in the range of 0.4 to 2 × ${10}^{16}$ ${\mathrm{cm}}^{-3\mathrm{}}$. Concurrent determinations of the electron densities and temperatures by various methods could not be fully reconciled and are critically discussed. The normalized experimental and theoretical profiles, when compared on the basis of equal peak separation, show increased broadening of the forbidden component and filling in of the dip in the observed profile.