JUNO high purity nitrogen plant
Appl Radiat Isot. 2024 Mar 21;208:111305. doi: 10.1016/j.apradiso.2024.111305. Online ahead of print.ABSTRACTThe Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kt low level radioactivity liquid scintillator detector in a laboratory 650 m underground. An excellent energy resolution and a large volume offer exciting opportunities for addressing many important topics in neutrino physics. High purity nitrogen is an important factor to ensure the low background of the JUNO detector. High Purity Nitrogen (HPN) is used for detector purging, pipe cleaning, and scintillator purification, among other things in JUNO. According to JUNO's requirements, the radon concentration in HPN should be less than 10 μBq/m3. To meet this requirement, A high-purity nitrogen plant with 100 Nm3/h maximum rate was designed and constructed. Low-temperature adsorption technology is used to remove radioactive impurities in nitrogen. High purification efficiency was ensured by using an activated carbon column with high column height-to-diameter ratio. Electrostatic collection and low-temperature enrichment methods are combined to measure radon in nitrogen. After ten days of continuous operation at 50 Nm3/h flux rate, the plant can to reduce the radon concentration in nitrogen from 37.4±1.8μBq/m3 to less than 1.33 μBq/m3. After HPN with flow rate of 50 Nm3/h passing through low-background pipeline (About 1.3 km), the radon concentration of HPN is 5.6±0.6μBq/m3.PMID:38537447 | DOI:10.1016/j.apr...
Source: Applied Radiation and Isotopes - Category: Radiology Authors: Xin Ling Boxiang Yu Zhilong Hou Tao Hu Li Zhou Yongjun Yan Zhihang Zhu Xiao Cai Yayun Ding Jian Fang Junyu Shao Lijun Sun Xilei Sun Yuguang Xie Xiaohui Qi Haodong Zhang Source Type: research