Enrichment of Double Beta Decay Isotope by Crown-ether & Microchip Chemical Plant

双β衰变是研究中微子绝对质量及其马约拉纳性质的重要研究之一，我们即将利用300千克的双β衰变核中q值最高的Ca <48>的CaF_2晶体进行candle实验。离心、扩散分离不能富集钙，电磁分离成本高，产量限制在几十克。建立了冠状醚液液萃取的化学同位素分离方法，得到了最高的分离系数为1.012（2℃）~1.014（20℃）（约为Jepson（1.008）的2倍和树脂（1.003）的5倍），并验证了微晶片对气液两相同位素交换反应和微混合器乳化滴萃取工艺的有效性。

The double beta decay, which can study the absolute neutrino mass and its Majorana nature, is one of the most important research and we will start CANDLES experiment soon utilizing 300kg of CaF_2 crystals containing of ^<48>Ca with the highest Q-value among double beta decay nuclei. The calcium cannot be enriched by centrifugal and diffusion separations and electromagnetic separation costs much and its production is limited only for tens of grams. We developed chemical isotope separation by liquid-liquid extraction with crown-ether and obtained the highest separation factor of 1.012(2℃)～1.014(20℃) (about two times of Jepson's 1.008 and five times of resin's 1.003) and showed the validity of microchip for the extraction process by gas-liquid two phase isotope exchange reaction and micromixer for emulsification droplets.