Electron-impact-excitation cross sections out of the $2{}^{3}S$ metastable level of helium at high energies

In this paper we report experimental measurements of the electron-impact-excitation cross sections out of the $2{}^{3}S$ metastable level of helium into higher excited levels, with emphasis on measurements at high electron energies. The agreement between our metastable results and recent theoretical calculations is comparable to the agreement between experimental and theoretical values for excitation from the ground state.