Atomic trajectories in compact cesium beam clocks

Accurate calculations are performed of atomic trajectories in conventional cesium beam tubes (CBTs) using dispersive, two-wire field magnets and also in a novel configuration using two orthogonal one-dimensional focusing dipoles of the type described by P. Kartaschoff (1969). In the first configuration, it was possible to explain observed differences in atomic velocity distribution in terms of small variations in oven and/or detector offsets. The second configuration yields beam intensities that are significantly higher than the ones obtained with dispersive magnets and/or substantially lower atomic velocities, and thus could improve the frequency stability of compact cesium clocks in the white-noise regime. Present design differs from P. Kartaschoff´s prescription in that a one-dimensional focussing dipole, rather than a hexapole or quadrupole magnet, is used as the A magnet in the CBT, making the tube manufacturing simpler