Speaker
Description
In this study, we evaluated and improved the simulation method of the DD neutron field in the OKTAVIAN facility at Osaka University, aiming to establish it as a standard neutron field. In previous studies [1], discrepancies were observed between the experimental angular distribution of DD neutron intensity and simulation results. To address this issue, we developed a new 3D simulation method for calculating the neutron source term, considering the scattering behavior of the incident deuterium beam in the target.
In the conventional 2D model, the relationship between the deuteron scattering angle η and the neutron emission angle φ was simplified, however, this approximation could not accurately reproduce the particle behavior. To solve this problem, we employed 3D calculation model by introducing two azimuthal parameters, α andβ, representing the orientations of the incident and scattered particles. The relationship amongη, φ, and the beam angle θ is expressed as
cosφ=cosηcosθ+sinηsinθcos(α-β)
A 3D Monte Carlo simulation based on this equation was performed to evaluate the neutron emission probability density under various conditions. As a result, an improvement was observed at large neutron emission angles.
In future, we will perform the theoretical verification of this simulation method.
References
[1] H. Matsunaga, R. Kawahata, S. Tamaki, and I. Murata, “Measurement and evaluation of DD neutron field characteristics for OKTAVIAN,” Proceedings of the Workshop on Nuclear Data 2022, Osaka, Japan, 2022.
