Inner balloon production for KamLAND-Zen 800
Inner balloon production for KamLAND-Zen 800
复制标题
KamLAND-Zen 800 的内气球生产
DOI：
10.1088/1742-6596/1468/1/012145
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
K. Ueshima and H. Watanabe for the KamLAND-Zen Collaboration
中科院分区：
文献类型：
--
作者：
A. Gando;Y. Gando;T. Hachiya;S. Hayashida;K. Hosokawa;H. Ikeda;S. Obara;H. Ozaki;K. Ueshima and H. Watanabe for the KamLAND-Zen Collaboration
Kamland-Zen用136Xe装载的液体闪烁体(LS)搜索无中微子双β衰变。LS容器是一个25μm厚的清洁尼龙内气球，是实验的关键，因为感兴趣区域的主要背景之一是来自内气球的214Bi。在KamLAND-Zen 400(2011年至2015年运行)中，尽管内气球是在一级超级洁净室制造的，但来自环境的灰尘污染限制了内气球的灵敏度。我们改进了KamLAND-Zen 800内气球的制作方法(于2019年1月开始DAQ)，并成功地将214Bi的本底水平与KamLAND-Zen 400的第二阶段相比降低到了十五分之一。介绍了内气球膜的材料和要求、改进的制造方案，包括清洁环境的建立和粉尘控制。
KamLAND-Zen searches for neutrinoless double-beta decay with 136 Xe loaded liquid scintillator (LS). The LS container, a 25-μm-thick clean nylon inner balloon is a key of the experiment since one of the main backgrounds in the ROI is 214 Bi from the inner balloon. In KamLAND-Zen 400 (operated from 2011 to 2015), dust contamination of the inner balloon from the environment limited the sensitivity, although the inner balloon was fabricated at a class-1 super clean room. We improved the production method of the inner balloon for KamLAND-Zen 800 (started DAQ in January, 2019) and successfully reduced the 214 Bi background level to one fifteenth as compared to the 2nd phase of KamLAND-Zen 400. The inner balloon film material and requirements, improved fabrication scheme, including establishment of clean environment and dust control, will be described.