Speaker
Description
KamLAND is a neutrino detector with a 1-kiloton liquid scintillator located 1000 meters underground in the Kamioka Mine in Japan. It successfully completed its 22-year KamLAND1 phase in 2024. Currently, the project is preparing to launch the KamLAND2 experiment within JFY2027, aiming for even higher performance.
To prepare for the start of the KamLAND2, the 13-meter-diameter balloon used to contain the liquid scintillator will be remanufactured. While the new balloon will follow the same material and design as the proven KamLAND1 balloon, several new efforts have been implemented to achieve even lower radioactivity. These include the introduction of a protective cover film to prevent contamination during production, research on film humidity management aiming for lower radioactivity than KamLAND1, and the adoption of low-radioactive materials for the suspension rope. In this presentation, I will report on the current status of the balloon production efforts and discuss their expected impact on the sensitivity of neutrino observations.