Rn removal system for Xe-based detectors using resonant ionization

氡是低能实验中的主要背景源之一。因此，在未来针对暗物质和无中微子双β衰变的大规模氙探测器中，抑制氡事件是必不可少的。虽然用蒸馏法从氙中除去氩和氪是公认的方法，但由于氡是从所有材料中连续散发出来的，所以不能使用这种技术。我们提出了一种新的氡去除方法氙使用共振增强多光子电离过程。可调谐激光器用于通过共振单光子或多光子吸收将氡原子提升到电子激发态，然后通过引入另一个光子将这些激发的氡原子电离。用这种方法，氡杂质可以选择性地电离和去除与施加的电场。在这项研究中，我们成功地证明了这一原则。

Radon is one of the major background sources in low energy experiments. Accordingly it is essential to suppress radon events in future large-scale xenon detectors aiming for dark matter and neutrino-less double beta decay. Although the removal of argon and krypton from xenon is well established using distillation, because radon is continuously emanated from all the materials, the technique cannnot be used. We propose a new radon removal method for xenon using a resonance-enhanced multiphoton ionization process. A tunable laser is used to promote radon atoms to an electronically excited state via resonant single- or multiple-photon absorption and these excited radon atoms are then ionized by the introduction of another photon. With this method radon impurities can be selectively ionized and removed with an applied electric field. In this study, we have successfully demonstrated this principle.