Experiments with trapped atoms

Norman F. Ramsey

The earliest trapped atom coherent resonance experiments were with material traps or bottles. In the atomic hydrogen maser the atoms are trapped inside a teflon-coated quartz bulb for about a second. Neutrons have been trapped for hundreds of seconds in suitably coated bottles or in superconducting magnetic traps. Results from experiments with trapped atoms and neutrons are given.

Galina A. Nemova

Jean Dalibard, Christophe Salomon

Takeshi Ikegami, Takayuki Kurosu, Shinichi Ohshima +1 more

Present status of laser cooling experiments in NRLM is presented. Laser cooling and trapping experiments for cesium atoms are continued in NRLM to develop an atomic fountain frequency standard. As a first step, we performed Cs atomic beam deceleration and trapping experiments. Atomic beam cesium atoms were decelerated by counterpropagating radiation from semiconductor laser diodes. The laser frequency was chirped to keep it in resonance with the decelerated atoms. The decelerated atoms were trapped by six mutually orthogonal laser beams in a magneto-optical trap configuration. The atoms could also be trapped directly from ambient cesium gas in a glass cell without using the deceleration laser beam. The characteristics of the trapped atoms are reported.

M. Colla

In this work I report on the development of a Magneto Optic Trap (MOT) for metastable helium atoms (He*). The metastable helium atoms are produced in a discharge nozzle source and collimated, slowed and compressed to provide a slow bright beam for loading the trap. The trap confines approximately 107 atoms, has a diameter of about 3 mm and with temperature approximately 1 mK. The trap is used for intra-trap and electron-atom scattering experiments. The results from these two experiments are reported. The electron scattering experiment is unique and employs a He* MOT for the first time, in combination with a new diagnostic technique (Phase Modulation Spectroscopy) to measure the trap loss. The results of these experiments have yielded the first total electron-metastable atom collision cross section measurements at intermediate (10-100 eV) electron energies.

Gerhard Backenstoss