Study of Double Beta Decay of 150Nd with KamLAND Detector

从无中微子双β衰变(0νββ)测量的角度出发，研制了载钕液体闪烁体(LS)和氙溶液闪烁体。测定了其最大溶出量、闪烁光产额和光学透明度等性能。结果发现^&lt；136&gt；Xe是一个很有前途的0νββ核。通过初步实验，确定了Xe溶解LS在卡姆兰德探测器中的安装方法。用400 kg^&lt；136&gt；Xe进行了两年的测量，估计了卡姆兰德中微子0νββ衰变对有效马约拉纳中微子质量的灵敏度为~50 meV。

The development of the Neodymium loaded liquid scintillator (LS) and Xenon dissolved LS was performed from the view point of neutrino-less double beta decay (0νββ) measurement. The properties such as maximum dissolved amount, scintillation light yield and optical transparency, were measured. As a consequence, it was found that ^<136>Xe was a promising 0νββ nucleus. The installation method of Xe dissolved LS into the KamLAND detector was established by the preliminary experiments. The sensitivity of the 0νββ decay in the KamLAND was estimated to be ~50 meV for the effective Majorana neutrino mass by using 400 kg of ^<136>Xe for 2 years measurement.