Design of a nitrogen purification system with cryogenic method for neutrino detection

In order to detect the neutrino with liquid scintillation detector, high-purity nitrogen is essential for gas stripping in this detector. Therefore, it is necessary to design a purification system for the detector to purify nitrogen. Using the method of low temperature adsorption for the purification system, the key designs including the flow path, the adsorber and the selection of activated carbon, are introduced in this study. In these designs, the selection of activated carbon is the most important because the adsorption characteristic of the carbon is related to the performance of the purification system. The method of grand canonical ensemble Monte Carlo is adopted to simulate the adsorption of radon by the activated carbon with its slit pore model. Using this method, the working temperature and the key characteristic of the activated carbon are obtained. •We present a flow path and a design of gas purification with cryogenic method.•We report the geometrical structure and design parameters of the adsorber.•The temperature of 77 K may be a proper working area for activated carbon.•Adsorption capacity rose as carbon slit pore radius went up at the temperature 77 K.•Carbon slit pore with larger radius maybe a good selection for radon adsorption.