Rubidium–xenon spin exchange and relaxation rates measured at high pressure and high magnetic field
Rubidium–xenon spin exchange and relaxation rates measured at high pressure and high magnetic field
复制标题
在高压和高磁场下测量的铷-氙自旋交换和弛豫率
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
D. Raftery
中科院分区：
文献类型：
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作者：
C. Rice;D. Raftery
在47000 G的高压条件下，研究了光泵Rb原子通过自旋交换产生超极化的Rb。 从可变的压力和温度的研究，自旋交换效率被发现是压力依赖性和低于可比的低场测量。由于短时间的二进制碰撞而产生的自旋交换被认为是与压强无关的，其截面被测量为<$σν <$SE=6.0（±0.1）×10−17 cm 3 s−1。 压力依赖性组分归因于Rb-双货车范德华（vdW）络合物的形成。在He缓冲气体中，Rb-PbvdW复合物的自旋交换速率常数为κ=1400（±100）s−1。这个值是可比的，虽然比以前测量的其他缓冲气体的vdW率稍小。当B 0为10000 G时，vdW配合物中的自旋交换很容易发生。 超精细相互作用的调制过程中的vdW复杂…
The production of hyperpolarized Xe via spin exchange with optically pumped Rb atoms was studied at 47 000 G under high-pressure conditions. From variable pressure and temperature studies, the spin exchange efficiency was found to be pressure dependent and lower than comparable low-field measurements. Spin exchange due to short binary collisions is expected to be pressure independent, and the cross section was measured to be 〈σν〉SE=6.0 (±0.1)×10−17 cm3 s−1. The pressure dependent component was attributed to the formation of Rb–Xe van der Waals (vdW) complexes. The rate constant for spin exchange in Rb–Xe vdW complexes was measured to be κ=1400 (±100) s−1 in He buffer gas. This value is comparable, though somewhat smaller than vdW rates measured previously for other buffer gases. While it is well known that spin exchange occurs readily in vdW complexes when B0 10 000 G is not accounted for in current theories. Modulation of the hyperfine interaction during the vdW comple...