4p-L-3 ^3He-Bの渦糸

弘樹 筒, 博一 藤坂

熈 神前

Mohammadou Mérawa, Didier Bégué

The dipole polarizabilities of the potassium atom in its ground (4 2S) and low-lying excited (4 2P, 5 2S) states have been calculated using the time-dependent gauge-invariant variational method [Mérawa, Rérat, and Pouchan, J. Chim. Phys. 91, 1387 (1994)]. The variation of these polarizabilities versus imaginary frequencies [Casimir and Polder, Phys. Rev. 73, 360 (1948)] have been computed, and the long-range dispersion coefficients for the molecular states of K2 dissociating to K(4S)+K(4S), K(4S)+K(4P), K(4P)+K(4P), K(4S)+K(5S), K(5S)+K(4P) and K(5S)+K(5S) have been evaluated. The results obtained for K(4S)+K(4P) interactions are in very good agreement with the recent experimental high-resolution photoassociative data of Wang et al. [J. Chem. Phys. 106, 7899 (1997)]. The long-range dispersion coefficients for the K(4P)+K(4P), K(4P)+K(5S) and K(5S)+K(5S) interactions are new.

敏雄 宗田

Guodong Wang

We present experimental studies on the spin-exchange optical pumping of 3He using alkali metal potassium vapor. High 3He polarizations are achieved using lower laser power than traditional rubidium-3He pumping studies. In addition, spin-exchange rate coefficient measurements for potassium-3He, rubidium-3He and cesium-3He pairs are reported. By spin-exchange optical pumping with potassium vapor, a high 3He polarization has been achieved in a mid-sized double-chamber glass target cell using only 5 watts of Ti:sapphire laser power. The spin-exchange rate coefficients of potassium-3He, cesium-3He and rubidium-3He pairs are measured and compared. The results are kSE = (4.0+/-0.3)E-20 cm3/sec for the potassium-3He pair, kSE = (6.5+/-0.4)E-20 cm3/sec for the rubidium-3He pair and kSE = (13.6 +/-1.3)E-20 cm3/sec for the cesium-3He pair. The results are consistent with theoretical predictions and confirm that the efficiency for spin-exchange polarization of 3He with potassium is significantly higher than with rubidium or cesium. The results motivate the development of high power diode lasers tuned to the appropriate potassium wavelengths. Applied to the production of polarized 3He as an atomic beam source for colliders, these developments could have significant impact on future studies of neutron spin structure. These studies may also have impact on magnetic resonance imaging using hyperpolarized 3He.

共憲 呉, 雅仁 中川, 修六 石川 +1 more