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 x 10(8) 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.