摘要
Purpose In the JUNO,the LS serves as the medium for detecting neutrinos.When purifying the LS using HPN,it is essential to ensure low background levels of radioactive krypton and argon in the HPN Methods Using the low-temperature physical adsorption properties of activated carbon to adsorb and separate radioactive gases such as radon,krypton,and argon from nitrogen in a liquid nitrogen environment.Results Our results indicated that the Kr concentration in the HPN purified by HP activated carbon is 6.84μBq/m,and the Ar concentration is 3.6μBq/m for overground HPN,while the Kr concentration is 31.4μBq/m for underground HPN.The^(85)Kr concentration in the nitrogen purified by coconut shell activated carbon is 0.46μBq/m.Conclusions After adsorption with activated carbon,the content of^(39)Kr and Ar in HPN is lower than the 50μBq/m required by JUNO.This work validates that the^(85)Kr and^(39)Ar concentrations in HPN is fit the JUNO requirement.
基金
supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA10010500).
