论文标题
磁化等离子体中原子极化的温度相关效应是高$^3 $ He核极化的有前途的特征
Temperature-related effects in the polarization of atoms in a magnetized plasma as a promising feature towards high $^3$He nuclear polarization
论文作者
论文摘要
我们报告了在磁场为3.66 t的磁场化血浆中氦3的核超极化的进一步研究，在相对较大体积的双电池中，在不同的实验条件下，与在Maul $ \ textit {et al。} $ [Phart。 Rev. A. $ \ textbf {98} $，063405（2018）]。已经发现，通过这种方法获得的稳态核极化会随温度和RF气体排出功率强烈增加。在设置中，我们设法在最高的温度下达到了近8％，这是该方法在10 MBAR处获得的最高极化。还表明，等离子体中的原子氧被认为是杂质的，可能是与PAMP工艺相关的血浆参数的良好探针，即温度或亚稳态$^3 $ HE密度。发现在室温附近稳定的细胞温度的极化构建速率为1 s $^{ - 1} $的订单，其尺寸的数量级比原始PAMP Paper中有关相同填充压力的数量级快。这些观察结果有助于通过这种方法进一步优化实验条件，以朝着强和快速的超极化。
We report on further investigation of nuclear hyperpolarization of helium-3 in magnetized plasma at a magnetic field of 3.66 T and at different experimental conditions in a dual cell of relatively large volume, compared to those reported in the original polarization of atoms in a magnetized plasma (PAMP) paper by Maul $\textit{et al.}$ [Phys. Rev. A. $\textbf{98}$, 063405 (2018)]. It was found that steady-state nuclear polarizations obtained by this method strongly increase with temperature and rf gas discharge power. We managed to reach almost 8% at the highest possible temperature in our setup which is to date the highest polarization obtained by this method at 10 mbar. It was also shown that atomic oxygen in plasma, considered as an impurity, could be a good probe of plasma parameters relevant for the PAMP process, either the temperature or the metastable $^3$He density. The polarization build-up rates with the cell temperature stabilized near room temperature are found to be of the order of 1 s$^{-1}$ which is by two orders of magnitude faster than was reported in the original PAMP paper for the same filling pressure. These observations promise a further optimization of experimental conditions towards strong and fast hyperpolarization by this method.
