Polarized He (23S) thermal metastable atom source

Abstract

A source of polarized He (23S) metastable atoms is described that provides a thermal energy beam with a flux of the order of ∼1014 metastables s−1 steradian−1 at a polarization Pz∼50%. The polarization of the beam can be simply reversed, or modulated, without changing the beam trajectory or flux. The beam contains no significant admixtures of He(21S) atoms, photons, or fast neutrals and is suitable for use in a wide variety of collision and surface physics experiments.