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Spin-exchange Optical Pumping of 3He with Rb/K Mixtures and Pure K



Wangchun Chen, Thomas R. Gentile, S E. Babcock, T G. Walker


We have studied the efficiency of spin-exchange optical pumping (SEOP) in cells that contain either pure rubidium, mixtures of rubidium and potassium, or pure potassium. Optical pumping was performed with spectrally narrowed diode array lasers operating at either the wavelength of the Rb 5s1/2 - 5p1/2 transition (795 nm) or the K 4s1/2 - 4p1/2 transition (770 nm). Calculations of the expected efficiency are shown for practical conditions and compared to measurements. We have measured the vapor pressure density ratio in Rb/K mixture cells using absorption of white light. Our focus is on the conditions that are relevantfor neutron spin filters, but the results are relevant to all applications of SEOP. We find that both Rb/K and pure K cells yield improvements in the spin-exchange efficiency, and each approach has its own advantages. Overall the best results for high polarizing rate with high polarization were obtained with Rb/K mixture cells with vapor density ratios between 2 and 6.
Physical Review A (Atomic, Molecular and Optical Physics)


alkali, helium, optical pumping, polarization, potassium, rubidium, spin-exchange


Chen, W. , Gentile, T. , Babcock, S. and Walker, T. (2007), Spin-exchange Optical Pumping of 3He with Rb/K Mixtures and Pure K, Physical Review A (Atomic, Molecular and Optical Physics), [online], (Accessed June 12, 2024)


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Created December 30, 2007, Updated October 12, 2021