Victor Tarasov | Searcharxiv

arXiv2026

Temperature-Dependent Neutron Moderation Model Including Inelastic Scattering in Reactor Media

In this study, a mathematical model of neutron moderation is developed that accounts for the temperature of the fissile medium and the contribution of inelastic neutron scattering on heavy nuclei of uranium 238 in reactor cores. Within the gas model framework, an analytical expression for the inelastic neutron scattering law for an isotropic neutron source is derived for the first time, incorporating the temperature of the moderating medium as a parameter. The scattering law is obtained from the general kinematic solution of inelastic neutron nucleus interactions in the laboratory system, where both particles possess arbitrary velocity vectors. Based on the newly derived inelastic and previously obtained elastic scattering laws, analytical formulas for the neutron flux density and moderation spectrum are presented, both of them dependents on the medium temperature. The calculated deceleration spectra exhibit two distinct maxima (a high energy and a low energy peaks). The low energy maximum is consistent with the analytical solution of the neutron balance equation, confirming the validity of the proposed model. The developed approach provides a deeper understanding of neutron energy distribution in temperature dependent reactor media and can be applied to improve the accuracy of neutron kinetic calculations in thermal and fast reactor systems.

physics.ins-det↗

arXiv2021

Strange Hadron Spectroscopy with Secondary KL Beam in Hall D

We propose to create a secondary beam of neutral kaons in Hall D at Jefferson Lab to be used with the GlueX experimental setup for strange hadron spectroscopy. The superior CEBAF electron beam will enable a flux on the order of $1\times 10^4~K_L/sec$, which exceeds the flux of that previously attained at SLAC by three orders of magnitude. The use of a deuteron target will provide first measurements ever with neutral kaons on neutrons. The experiment will measure both differential cross sections and self-analyzed polarizations of the produced $Λ$, $Σ$, $Ξ$, and $Ω$ hyperons using the GlueX detector at the Jefferson Lab Hall D. The measurements will span CM $\cosθ$ from $-0.95$ to 0.95 in the range W = 1490 MeV to 2500 MeV. The new data will significantly constrain the partial wave analyses and reduce model-dependent uncertainties in the extraction of the properties and pole positions of the strange hyperon resonances, and establish the orbitally excited multiplets in the spectra of the $Ξ$ and $Ω$ hyperons. Comparison with the corresponding multiplets in the spectra of the charm and bottom hyperons will provide insight into he accuracy of QCD-based calculations over a large range of masses. The proposed facility will have a defining impact in the strange meson sector through measurements of the final state $Kπ$ system up to 2 GeV invariant mass. This will allow the determination of pole positions and widths of all relevant $K^\ast(Kπ)$ $S$-,$P$-,$D$-,$F$-, and $G$-wave resonances, settle the question of the existence or nonexistence of scalar meson $κ/K_0^\ast(700)$ and improve the constrains on their pole parameters. Subsequently improving our knowledge of the low-lying scalar nonet in general.

nucl-ex↗