Δ-Kick and Raman Cooling on a Cesium Atomic Fountain
Atomic clocks similar to the most precise clocks in existence are presently being developed for installation on the International Space Station. The microgravity environment will allow for longer measurement times (factors of 3) and thusincreased accuracy. Further increases in the measurement time require new techniques for achieving lower thermal velocities of the atomic cesium sample. Two such techniques are in development. One method, called delta-kick cooling, a form of magnetic lensing using a pulsed field, trades density for very low velocities. The second method uses pulsed lasers to exploit the ability of two-photon Raman processes to cool to temperatures below the single-photon recoil limit.