The development of $^{222}$Rn detectors for JUNO prototype

Understand

The radioactive noble gas $^{222}$Rn, which can be dissolved in water, is an important background source for JUNO.

• In this paper, based on the water system of JUNO prototype, two kinds of high sensitivity radon detectors have been proposed and developed.
• The sensitivity of Si-PIN Rn detector, which uses a Si-PIN photodiode to detect the $\alpha$ from $^{214}$Po decay, is $\sim$9.0~mBq/m$^3$.
• The sensitivity of LS Rn detector, which uses liquid scintillator to detect the coincident signals of $\beta$ from $^{214}$Bi decay and $\alpha$ from $^{214}$Po decay, is $\sim$64.0~mBq/m$^3$.