Internal Calibration of the PandaX-II Detector with Radon Gaseous Sources

Understand

We have developed a low-energy electron recoil (ER) calibration method with $^{220}$Rn for the PandaX-II detector.

• $^{220}$Rn, emanated from natural thorium compounds, was fed into the detector through the xenon purification system.
• From 2017 to 2019, we performed three dedicated calibration campaigns with different radon sources.
• We studied the detector response to $\alpha$, $\beta$, and $\gamma$ particles with focus on low energy ER events.