Magnetic trapping of metastable calcium atoms

Metastable calcium atoms, produced in a magneto-optic trap (MOT) operating within the singlet system, are continuously loaded into a magnetic trap formed by the magnetic quadrupole field of the MOT. At MOT temperatures of 3 mK and 240 ms loading time, we observe 1.1×10⁸ magnetically trapped ³P₂ atoms at densities of 2.4×10⁸cm^-3 and temperatures of 0.61 mK. In a modified scheme, we first load a MOT for metastable atoms at a temperature of 0.18 mK and subsequently release these atoms into the magnetic trap. In this case, 240 ms of loading yields 2.4×10⁸ trapped ³P₂ atoms at a peak density of 8.7×10¹⁰cm^-3 and a temperature of 0.13 mK. The temperature decrease observed in the magnetic trap for both loading schemes can be explained only in part by trap size effects.