Excitation of the $n {}^{1}S$ States of Helium by Proton Impact and the $n^{- 3}$ Rule

Recently calculated cross sections for the excitation of the

n {}^{1}S (n = 4 to 7)

states of helium displayed as a function of

n^{- 3}

show an anomalous behavior of the

7 {}^{1}S

cross sections. This anomalous behavior has been traced to the 40-term correlated wave function used to represent the

7 {}^{1}S

state. A more accurate 40-term wave function has been used to recalculate the

7 {}^{1}S

excitation cross sections. The cross sections are changed only by about 5%, but they now fit the pattern as far as the

n^{- 3}

dependence is concerned.

This publication has 2 references indexed in Scilit:

Excitation of thenS1States of Helium by Proton Impact and then−3Rule