The 2 3S - 2 3P, 3 3P, 3 3D, 4 3D Excitations of Helium Atoms by Electrons

Abstract

Born's approximation is used to calculate the cross sections for the excitation of the 2 ³ P, 3 ³ P, 3 ³ D and 4 ³ D states of helium from the metastable 2 ³ S state by electrons with energies ranging from the thresholds of the processes to about 100 eV. In the case of the 2 ³ S – 2 ³ P excitation a close coupling formula due to Seaton is also used.