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Optical pumping and population transfer of nuclear-spin states of caesium atoms in high magnetic fields 下载免费PDF全文
Nuclear-spin states of gaseous-state Cs atoms in the ground state
are optically manipulated using a Ti:sapphire laser in a magnetic
field of 1.516T, in which optical coupling of the nuclear-spin
states is achieved through hyperfine interactions between electrons
and nuclei. The steady-state population distribution in the
hyperfine Zeeman sublevels of the ground state is detected by using
a tunable diode laser. Furthermore, the state population transfer
among the hyperfine Zeeman sublevels, which results from the
collision-induced modification \delta a(\bm S \cdot \bm I) of the
hyperfine interaction of Cs in the ground state due to stochastic
collisions between Cs atoms and buffer-gas molecules, is studied at
different buffer-gas pressures. The experimental results show that
high-field optical pumping and the small change \delta a(\bm S
\cdot \bm I) of the hyperfine interaction can strongly cause the
state population transfer and spin-state interchange among the
hyperfine Zeeman sublevels. The calculated results maybe explain the
steady-state population in hyperfine Zeeman sublevels in terms of
rates of optical-pumping, electron-spin flip, nuclear spin flip, and
electron-nuclear spin flip-flop transitions among the hyperfine
Zeeman sublevels of the ground state of Cs atoms. This method may be
applied to the nuclear-spin-based solid-state quantum computation. 相似文献
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辐射阻尼现象通常只有在高磁场中,利用高分辨率谱仪,才能观测到液态,像水质子这样具有大自旋浓度的信号。但是我们在低场流动系统中,利用光泵自旋交换的方法,获得高度极化的^129Xe气体,从而使我们能观测到,流动系统下超极化^129Xe的气态辐射阻尼信号。 相似文献
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利用中间玻色子理论和Cabibbo的弱相互作用SU3模型,求得了中微子-核子“弹性”反应ν1+N→l+B的微分截面和终态粒子纵极化的解析表式,并对若干过程进行了数值计算。结果表明:对给定的一组形状因子,当中微子能量足够高时,在适当的出射角附近,轻子和超子的纵极化的中间玻色子效应相当明显;如实验数据足够精确,将极化与微分截面相结合。可估计中间玻色子质量,并给出形状因子的一些知识。还估计了νμ[Z,A]→μ-+[Z+1,A]过程的μ-纵极化的核效应和中微子能谱的影响。 相似文献
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使用频率可扫描的窄线宽半导体激光,通过共振吸收方法获得强磁场下Cs(6S_1/2→6P_1/2)在不同种类和不同压力的惰性气体中的吸收线型。利用Voigt线型公式对不同的实验线型进行拟合,从而求得压力增宽系数。实验表明,在低于1.33×10 ̄4Pa范围内,碰撞增宽与压力成线性关系。 相似文献
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光泵的方法被用来确定K~(39)Xe~(129)范德瓦耳斯分子中的自旋-转动耦合常数对自旋交换耦合常数的比值X。详细地讨论了这些测量理论。 得到比值X=γN/α=4.8(1)。 相似文献
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THE 82S1/2→62D EXCITATION TRANSFER OF RUBIDIUM ATOMS INDUCED BY COLLISIONS WITH GROUND-STATE RUBIDIUM AND HYDROGEN MOLECULES 下载免费PDF全文
The processes of excitation transfer from the 82S1/2 state to the 62D state of rubidium in Rb(82S1/2)-Rb(52S1/2) and Rb(82S1/2)-H2 collisions have been studied experimentally. During irradiating the Rb vapor, mixed with H2, by two light beams for selective stepwise excitation, the Rb 82S1/2→52P3/2 direct fluorescence and the Rb 62D3/2→52P1/2 sensitized fluorescence have been measured as a function of H2 gas pressure. The measurements yielded the cross-sections σ(82S1/2→62D) and σ*(82S1/2→62D) of Rb 82S1/2→62D excitation tranfer induced by collisions with 52S1/2 atom and H2 molecules respectively. The results are discussed in detail. 相似文献
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激光极化129Xe的生物磁共振成像研究进展 总被引:1,自引:0,他引:1
激光光抽运自旋交换方法能够极大地增强^129Xe核自旋极化,其获得的非平衡极化度远远高于在相同磁场里玻尔兹曼平衡值。 相似文献