Internal calibration of the PandaX-II detector with radon gaseous sources

Abstract

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 𝛼, 𝛽, and 𝛾 particles with focus on low energy ER events. During the runs in 2017 and 2018, the amount of radioactivity of 222 Rn were on the order of 1% of that of 220 Rn and thorium particulate contamination was negligible, especially in 2018. We also measured the background contribution from 214 Pb for the first time in PandaX-II with the help from a 222 Rn injection. Calibration strategy with 220 Rn and 222 Rn will be implemented in the upcoming PandaX-4T experiment and can be useful for other xenon-based detectors as well.

Determination of responses of liquid xenon to low energy electron and nuclear recoils using the PandaX-II detector

“…The details of 220 Rn calibration setup and operation in PandaX-II can be found in Ref. [9]. The injection system consisting of a mass flow controller and a 232 Th source chamber with filters upstream and downstream, is shown in Fig.…”

A Search for Light Fermionic Dark Matter Absorption on Electrons in PandaX-4T

“…The detector ER response is calibrated by the 220 Rn injection data (see Ref. [39] for the method). The model based on the noble element simulation techniques (NEST v2.2.1) [40,41] is then used to fit the data below 30 keV, shown in Fig.…”

The half-life of $$^{212}$$Po

“…In Ref. [27] a radon gaseous source was used to calibrate the xenon liquid/gas time-projection chamber of the PandaX-II experiment obtaining T 1/2 = 297(6) ns with quite big uncertainty comparing with those in the last experiments in Table 1.…”