The application provides a
simulation prediction method and
system for slow
positron source intensity in a
research reactor, comprising the following steps: S1, reading arrangement information of components in a reactor core of the
research reactor; S2, constructing a Monte Carlo model of the reactor core containing a slow
positron source device, and obtaining
neutron multi-group angular flux and
photon multi-group angular flux information near the slow
positron source generating device; S3, constructing a slow positron Monte Carlo model; S4, performing energy-angle double sampling to obtain an incident
neutron energy probability
density distribution function f n,ig,ia , an angle probability
density distribution function f n,ia , an incident
photon flux energy probability
density distribution function f g,ig,ia , an angle probability
density distribution function f g,ia , and a
neutron-
photon weight factor; S5, performing function sampling of particle types, energy and angle; and S6, obtaining slow positron distribution information generated in the slow positron generating device. The application accurately considers the whole life cycle of slow positron generation and transportation through multi-stage
coupling, and realizes accurate prediction of slow positron source intensity.