Speaker
Description
KamLAND-Zen experiment is a low background liquid scintillator (LS) detector and searches for neutrino-less double-beta decay (0$\nu\beta\beta$) of $^{136}$Xe. In order to suppress backgrounds proportional to volume (cosmo-genic muon spallation products, solar $^{8}$B $\nu$, etc.), $^{136}$Xe loaded LS is stored in the 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 for 0$\nu\beta\beta$ search. Although $^{214}$Bi could be rejected by tagging with $^{214}$Po, the $\alpha$ from $^{214}$Po is absorbed in the nylon IB. If the IB is made of a scintillation film, it enables us to detect the $\alpha$ and tag $^{214}$Bi. Therefore, we are planning to use a scintillation film for an IB in a future project, KamLAND2-Zen. In this presentation, we describe a performance of the scintillation IB and its potential for pulse shape discrimination.
