Beam of metastable krypton atoms extracted from a rf-driven discharge

A rf-driven discharge is used to produce a beam of metastable krypton atoms at the 5s(3/2)2 level with an angular flux density of 4×1014 s−1 sr−1 and most probable velocity of 290 m/s, while consuming 7×1016 krypton atoms/s. When operated in a gas-recirculation mode, the source consumes 2×1015 krypton atoms/s with the same atomic-beam output.