Potential Of Geo-neutrino Measurements At JUNO

Geoneutrinos are anti-neutrinos produced by the beta decay of heat elements such as U,Th and K inside the Earth.Neutrinos have a small cross-section and can pass straight through the Earth without reacting or being absorbed by other matter,making it suitable for probing deep inside the Earth.The detection of geoneutrinos could help build a bridge between particle physics and earth science.providing unique insights into some of the most hotly debated questions in earth science,such as the source of Earth’s heat flow and its origin.According to the published detection data from the KamLAND Collaboration and Borexino collaboration,the possibility of geoneutrino detection has been confirmed.However,due to the limitation of the detector volume used in the experiment,There are low statistics in the detected geoneutrinos,which makes them difficult to reconstruct the Earth’s information.It is not only impossible to distinguish neutrinos from the mantle and the crust,but also impossible to distinguish different mantle models.The JUNO detector currently under construction in southern China will have 20 kilotons of liquid scintillation.It takes only one year of operation time to record more geoneutrino events than all previous detectors,which is expected to achieve internationally leading results in Th/U ratio and mantle radioheat generation.In this paper,the expected signal of JUNO detector under different earth models is introduced and the corresponding visible energy spectra of geoneutrino is given.The difference between the real oscillation probability and the average oscillation probability in the calculation of the expected signal of geoneutrino is used to quantitatively evaluate the influence of oscillation effect on the shape of the energy spectrum.Geoneutrino sensitivity study in the Yellow Book is updated using the newly parameters published by JUNO collaboration,combining the least-square method and the chi-square function.We mainly updated the input energy spectrum,including the updating of the reactor neutrino background,the geoneutrino signal and the non-reactor neutrino background.The difference between the Yellow Book and the updated inputs in calculating total geoneutrino precision and measuring uranium and thorium geoneutrino precision is compared.The effects of systematic errors such as background errors,spent fuel errors,non-equilibrium elements and Daya Bay energy spectrum anomalies on the precision of neutrino measurement are quantitatively studied.Finally,based on the difference of the the chi-square function value calculated by changing the error of the crustal neutrino,the degree of differentiation between the crust neutrino and the mantle neutrino is explored.The precision of different local crustal models in measuring the mantle neutrino is analyzed.The global model can detect Mantle neutrinos at the confidence level of 2σ.