Babcock Earl, Nelson Ian, Kadlecek Steve, Driehuys Bastiaan, Anderson L W, Hersman F W, Walker Thad G
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Phys Rev Lett. 2003 Sep 19;91(12):123003. doi: 10.1103/PhysRevLett.91.123003. Epub 2003 Sep 16.
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 collisions approaches 1/4, an order of magnitude greater than achieved by pure Rb pumping. We present the first measurements of actual photon efficiencies (polarized nuclei produced per absorbed photon), and show that a new parasitic absorption process limits the total efficiencies for both hybrid and pure Rb pumping.
我们展示了使用“混合”钾 - 铷蒸汽混合物对³He进行自旋交换光抽运。铷原子吸收来自标准795nm激光器的光，然后通过碰撞使钾原子极化。钾原子与³He原子之间的自旋交换碰撞随后以比铷 - ³He更高的效率将角动量传递给³He。对于富含钾的蒸汽，混合自旋交换碰撞的效率接近1/4，比纯铷抽运所达到的效率高一个数量级。我们首次测量了实际的光子效率（每吸收一个光子产生的极化原子核），并表明一种新的寄生吸收过程限制了混合抽运和纯铷抽运的总效率。
