Collisional Relaxation Processes for the n=3 States of Helium. I. Excitation Transfer by Normal Atoms and by Electrons

The positive column of a glow discharge through helium served as a reactor where each of the n=3 states of helium was selectively modulated by absorption of radiation. By monitoring the in-phase component of radiation from adjacent n=3 states over a range of discharge currents and pressures, rate constants were determined for transfer of excitation between n=3 states by collision with normal atoms and with electrons.