Simultaneous Magneto-Optical Trapping of a Boson-Fermion Mixture of Metastable Helium Atoms

We simultaneously confine fermionic metastable ³He atoms and bosonic metastable ⁴He atoms in a magneto-optical trap. The trapped clouds, containing up to 1.5×10⁸ atoms of each isotope, are characterized by measuring ions and metastable helium atoms escaping from the trap. Optical pumping of ³He atoms to a nontrapped hyperfine state is investigated and it is shown that large atom numbers can be confined without additional repumping lasers. Unique possibilities for quantum degeneracy experiments with mixtures of spin-polarized metastable ³He and ⁴He atoms are indicated.