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June 22, 2020 to July 2, 2020
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Scintillation balloon for neutrino-less double-beta decay search with a liquid scintillator detector

Not scheduled


Mr Rikuo Nakamura (Tohoku university)


KamLAND-Zen experiment is a neutrino-less double-beta decay search experiment with $^{136}$Xe and the low background liquid scintillator (LS) detector.
In order to suppress backgrounds proportional to volume, $^{136}$Xe loaded LS is stored in an inner balloon (IB) made of nylon.
The IB was made as clean as possible. However, the contamination of $^{238}$U still remains, and its daughter nuclei $^{214}$Bi will be one of the largest backgrounds.
Although $^{214}$Bi could be rejected by delayed coincidence tagging with $\alpha$-ray from $^{214}$Po, the tagging efficiency is not high enough due to the $\alpha$-ray absorption in nylon IB.
To detect the $\alpha$-ray and tag $^{214}$Bi, we are planning to use a scintillation film for the IB in a future project, KamLAND2-Zen.
In this presentation, we describe the performance of scintillation IB and its potential for a pulse shape discrimination.


Scintillation balloon can reduce the backgrounds of KamLAND2-Zen.

Experiment/Collaboration KamLAND-Zen

Primary author

Mr Rikuo Nakamura (Tohoku university)


Dr Haruo Ikeda (Tohoku University) Dr Koji Ishidoshiro (Tohoku University) Dr Sei Ieki (Tohoku University) Dr Syuhei Obara (Tohoku University) Dr Yoshihito Gando (Tohoku University)

Presentation Materials