Electron impact excitation of resonances below the n=3 levels of atomic hydrogen

Abstract
The excitation of hydrogen atoms to the n=2 states by electrons is studied for impact energies from 10.9 to 12.1 eV. The effect of resonances below the n=3 threshold on scattering cross sections is studied in detail. The calculations employ the algebraic variational method and a basis of 14 functions, including six atomic eigenstates and eight pseudostates.