Precise Measurement of Refractive Index of Liquid Xenon Scintillator

我们用自行研制的装置测量了液体氙闪烁体对闪烁光的折射率，测量精度优于0.01。主要结果如下：-我们成功地获得了在10^5 Pa下与气相平衡的液态氙的折射率，误差最小为0.007。折射率随波长从可见光到真空紫外区的变化范围为1.38 ~ 1.71。在可见光区，测量值与以前的高精度实验结果一致。折射率的波长依赖性遵循众所周知的Sellmeier色散方程。在真空紫外区，我们同样在0.9 × 10 ^5和1.2 × 10 ^5 Pa下测量了与其气体平衡的折射率，以观察折射率的微小变化。我们发现，密度依赖性很好地解释了洛伦兹-洛伦兹关系。所得指数值与以往的任何指数值都有显著差异 ...更多信息 在真空紫外区的研究。我们讨论了产生差异的原因，并指出了造成误差的可能原因。我们已经证实了我们的实验声称的高精度的基础上额外的校准工作。研究的进展和结果已在各种学术会议和硕士论文中报告。部分结果已被国际稀有气体探测器专著所引用，指出折射率和闪烁谱是计算氙液体中瑞利散射长度的重要量，而闪烁谱还不是很清楚。此外，我们还揭示了一个新的问题，涉及的相变氙作为副产品。此外，我们还揭示了一个新的问题，涉及的相变氙作为副产品。研究结果表明，在一定压力下，氙的沸点可能比已知值高出约1 K。这种差异对于折射率的研究来说是微不足道的，但它很重要，应该通过未来对液体氙的各种应用的研究来解决。少

We have measured refractive index of liquid xenon scintillator for scintillation light with good precision of less than 0.01 by using originally developed apparatus. The main results are the following :- We have successfully obtained the refractive index of liquid xenon in equilibrium with its gas phase at 10^5 Pa with a least error of 0.007. The value of the index varies from 1.38 to 1.71 as a function of wavelength from visible to vacuum-ultraviolet region. At visible region, the measured values are consistent with those by previous high-precision experiment. The wavelength dependence of the index is followed by well-known Sellmeier dispersion equation.- At vacuum-ultraviolet region, we measured the index also at 0.9x10^5 and 1.2x10^5 Pa similarly in equilibrium with its gas to observe slight change of the index. We found out that the density dependence is well explained by Lorentz-Lorenz relation.- The obtained value of the index is significantly different with any values of previou … More sly studies at vacuum ultraviolet region. We discuss the reasons of the difference and pointed out that the possible cause of errors in the previous experiments. We have confirmed the claimed high precision of our experiment based on additional calibration works.- The progress and the results of the study have been reported at various academic meetings as well as in master's theses. A part of the results has been referred in an international book on noble gas detectors.We have pointed out that the refractive index is important quantity to calculate Rayleigh scattering length in xenon liquid, together with scintillation spectrum which is still not well known yet. In addition, we have revealed a new problem involved in phase transition of xenon as a by-product. In addition, we have revealed a new problem involved in phase transition of xenon as a by-product. The results of the study indicate that the boiling point of xenon might be about 1 K higher than known value at a pressure. This discrepancy is negligibly small enough for the study of the refractive index, but it is important and should be resolved by future studies for various applications of liquid xenon. Less