The N=3 series of the ${}_{}{}^1{}_{}{}^{}\mathrm{S}_{}^{\mathrm{e}}{}_{}{}^{}$ helium states have been investigated by partial-wave analysis and by observing the shape densities. The K-classification scheme has been recovered. The strong radial-radial correlation region (SRRCR) has been found. The process of energy transfer occurring inside the SRRCR has been inspected in detail and two types of mechanisms, the ‘‘direct push’’ and the ‘‘head-on collision,’’ have been discovered.

• Received 10 April 1989

DOI:https://doi.org/10.1103/PhysRevA.40.4849