Optical pumping in 3He with a laser

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...

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...

A broadband Ytterbium-doped tunable fiber laser for 3He optical pumping at 1083 nm

Large amounts of hyperpolarized He gas with high nuclear polarization rates are required for use in neutron spin filters or nuclear magnetic resonance imaging of human lung. Very high efficiency can be obtained by metastability exchange optical pumping using multimode lasers to excite the 2S-2P transition at 1083 nm. Broadband Ytterbium-doped tunable fiber lasers have been designed for that par...

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

4He optical pumping with intensity modulated laser light

4He (2 3Si) metastable atoms are optically pumped with intensity modulated light The use of a single mode diode-pumped LNA laser as the pumping source, allows the study of resonance signals predicted'by the optical pumping theory but not yet observed Resonances are detected on the transmitted pumping beam at the modulation frequency and its harmonics Application of this method to high sensitivi...