Development of Neutronic Model of Hybrid DEMO-FNS Reactor by Means of NESTOR Code and Monte Carlo Method

The paper is devoted to the creation of an improved neutron plasma model of the hybrid reactor facility (HRF) DEMO-FNS, which has been used by codes implementing the Monte Carlo method for modeling radiation transport (MCNP and SuperMC). The old simplified model of the neutron source did not take into account the effect of the neutral injection on the intensity distribution of the fusion reaction rate, and it also had an unrealistic shape (ellipsoidal in vertical section). A new model has been developed on the basis of current data of temperature and density distributions in plasma. The model is built on the basis of current ideas about temperature and density distributions in plasma, takes into account the high contribution of neutral injection to the formation of a population of fast ions, and is also specified by an array of elementary volumes. This makes it possible to set an arbitrary shape of the neutron generation intensity distribution with the required accuracy. The influence of the plasma shape on the distribution of the primary (not scattered) neutron flux along the poloidal angle, as well as on neutron transfer and related processes outside the plasma (in the blanket, and first wall), is shown.