DYNAMICS OF COLD ATOMS IN A QUADRUPOLE MAGNETIC TRAP WITH AN ORBITINGPOTENTIAL

We study the dynamics of aroma confined to a quadrupole magnetic trap with an orbiting potential. For typical values of the experimental par ameters of the trap, the rotating magnetic field is shown to produce h igh-frequency modulation of atomic momenta with an amplitude comparabl e to the widths of the momentum distributions for the lowest oscillati on states of atoms in the time-averaged potential. We find the quantum -statistical momentum and position distributions of atoms and show tha t at temperatures much higher than the effective vibrational temperatu re of the atoms in the trap the quantum-statistical momentum and posit ion distributions are Gaussian. We also establish that at temperatures comparable to the effective vibrational temperature of the atoms the quantum-statistical momentum distribution has an annular structure in the trap's symmetry plane, which is due to the deep modulation of the atomic momenta caused by the rotating magnetic field, (C) 1998 America n Institute of Physics.