Magnetooptical compression of atomic beams

We consider the propagation of an atomic beam in a quadrupole magnetic field under transverse irradiation by a cooling laser field. The cooling laser field was chosen in the form of a two-dimensional σ+-σ- configuration. We show that the sub-Doppler resonance in the radiation force can be used to reduce the diameter of the atomic beam to a value on the order of 10 μm. We establish that the simultaneous transverse cooling and compression of the atomic beam allow its phase density to be increased to values of the order of 10-4-10-3. The dipole interaction of an atom with the cooling and compressing laser field in a quadrupole magnetic field is analyzed in terms of a simple (3 + 5)-level model atom