Liquid crystal polarimetry for metastability exchange optical pumping of 3He

Hybrid spin-exchange optical pumping of 3He.

We demonstrate spin-exchange optical pumping of 3He using a "hybrid" K-Rb vapor mixture. The Rb atoms absorb light from a standard laser at 795 nm, then collisionally polarize the potassium atoms. Spin-exchange collisions of K and 3He atoms then transfer the angular momentum to the 3He with much greater efficiency than Rb-3He. For a K-rich vapor, the efficiency of the hybrid spin-exchange colli...

On the limits of spin-exchange optical pumping of 3He

Optical pumping in 3He with a laser

2014 Optical pumping of ground state 3He has several peculiar features because nuclear polarization is first obtained in the metastable 2 3S state and then transferred to the ground state (indirect optical pumping); this introduces non-linearities in the equation of evolution of the populations. Here we present a numerical calculation of the kinetics of optical pumping in 3He, which allows a de...

Limits to the polarization for spin-exchange optical pumping of 3He.

Based on measurements of the temperature dependence of 3He relaxation in a wide range of spin-exchange optical pumping cells, we report evidence for a previously unrecognized surface relaxation process. The relaxation rate was found to be linearly proportional to the alkali-metal density with a slope that exceeds the spin-exchange rate, which limits the polarization for current applications, in...

Effects of high intensity neutron flux on in-situ spin-exchange optical pumping of 3He

Prior studies revealed neutron beam-induced alkali-metal spin relaxation in He cells polarized in-situ by spin-exchange optical pumping. These effects are minor for neutron beams of low to moderate intensity, but become important at the highest neutron flux levels available in the full spectrum beams of high flux neutron sources. It was found that the relaxation consisted of a fast and a slow c...