Ferromagnetic atom guide with in situ loading

Magneto-optic and magnetostatic trapping is realized near a surface using current carrying coils wrapped around magnetizable cores, with up to 10{sup 9} cesium atoms. Ramping up the current while maintaining optical dissipation leads to tightly confined atom clouds with an aspect ratio of 1:1000. We study the three-dimensional character of the magnetic potential and characterize the atom number and density as functions of the applied current. The field gradient in the transverse dimension has been varied from 1 kG/cm.