Radiogenic neutron background in reactor neutrino experiments

We report a novel correlated background in the antineutrino detection using inverse beta decay reaction. Spontaneous fissions and $(\ensuremath{\alpha},n)$ reactions peripheral materials of detector, such as borosilicate glass photomultipliers, produce fast neutrons prompt gamma rays. If shielding from material to detector target is not thick enough, gammas could enter volume mimic signals. This paper revisits yields energy spectra produced $\mathrm{B}(\ensuremath{\alpha},n)\mathrm{N}$ $\mathrm{F}(\ensuremath{\alpha},n)\mathrm{Na}$ reactions. A Geant4 based simulation has been carried out simplified geometry for present generation reactor neutrino experiments. The rates these experiments are estimated. this was taken into account, value mixing angle ${\mathrm{sin}}^{2}2{\ensuremath{\theta}}_{13}$ would be underestimated. recommend that Daya Bay, RENO, Double Chooz, JUNO, carefully examine masses radiopurity levels close rich boron fluorine.