Intensities of helium Stark lines in the region of levels anticrossing between n=6 and n=7

Studies of intensities of Stark lines of atomic He have been performed. The applied fields were high enough that shifts of the upper levels of the observed transitions became larger than the separation distance between levels with different principal quantum numbers. Overlapping of structures belonging to neighboring principal quantum numbers leads to levels anticrossing effects, what is reflected in variation of intensities of the observed spectral lines. Using the density matrix theory, calculations of the line intensities have been performed. By matching the superpositions of the excited states in the theoretical calculations we can follow the results of observation. Computer simulations have been performed for the observed levels anticrossing region between n = 6 and n = 7 in the second triplet series (23P–n3Q, Q = S, P, D, ...).