Continuous loading of a magnetic trap

Abstract

We have realized a scheme for continuous loading of a magnetic trap (MT). ${}^{52}\mathrm{Cr}$ atoms are continuously captured and cooled in a magneto-optical trap (MOT). Optical pumping to a metastable state decouples atoms from the cooling light. Due to their high magnetic moment $(6 {\ensuremath{\mu}}_{B}),$ low-field seeking metastable atoms are trapped in the magnetic quadrupole field provided by the MOT. Limited by inelastic collisions between atoms in the MOT and in the MT, we load ${10}^{8}$ metastable atoms at a rate of ${10}^{8}$ atoms/s below $100 \ensuremath{\mu}\mathrm{K}$ into the MT. Optical repumping after the loading allows us to realize a MT of ground-state chromium atoms.