  At low magnetic field, metastability exchange optical pumping of helium-3 is
known to provide high nuclear polarizations for pressures around 1 mbar. In a
recent paper, we demonstrated that operating at 1.5 T can significantly improve
the results of metastability exchange optical pumping at high pressures. Here,
we compare the performances of two different optical pumping lines at 1.5 T,
and show that either the achieved nuclear polarization or the production rate
can be optimized.
