51 research outputs found
Neutron Moderation Theory Taking into Accout the Thermal Motion of Moderating Medium Nuclei
In this paper we present the analytical expression for the neutron scattering
law for an isotropic source of neutrons, obtained within the framework of the
gas model with the temperature of the moderating medium as a parameter. The
obtained scattering law is based on the solution of the kinematic problem of
elastic scattering of neutrons on nuclei in the L-system in the general case.
I.e. both the neutron and the nucleus possess the arbitrary velocity vectors in
the L-system. For the new scattering law the flux densities and neutron
moderation spectra depending on the temperature are obtained for the reactor
fissile medium. The expressions for the moderating neutrons spectra allow
reinterpreting the physical nature of the underlying processes in the thermal
region.Comment: 26 pages, 6 figure
Experimental evidence of dark matter axions identical to solar axions and the absence of the "fifth" carrier force for the Higgs field
The complete "experimental" proof of the existence of axion luminosity and
trapped ADMs in the interior of the Sun is the reason for the formation of hot
dark matter axions (see modified Turner model (1987) with a critical density
fraction of at a mass of )
between inflation and Big Bang nucleosynthesis, which are further transformed
into mixed dark matter between Big Bang nucleosynthesis and the cosmological
microwave background (CMB) in the form of and , where the first term 5 GeV ADM
is the result of the decay of the partially composite dark matter of the Higgs
boson, in which there is a remarkable absence of the "fifth" carrier force for
the Higgs field in the Universe, and the second term
is associated with the
mass of of coherent axions of warm dark matter,
which are identical to solar axions with the same mass (Rusov et al. 2021).Comment: 28 pages, 7 figure
GEANT4 simulation of the moderating neutrons spectrum
The probability and intensity of nuclear reactions involving neutrons are
characterized by the corresponding reaction cross-sections which are known to
depend strongly on the incident neutron energy. In real applications the
neutrons are seldom or never monoenergetic, and are usually characterized by
certain continuous energy spectrum. The detailed knowledge of the neutron
spectrum is crucial for numerous applications such as the nuclear reactor
operation, the traveling wave reactor (TWR) development, including the search
of the neutron energy ranges suitable for the wave nuclear burning, the search
and prediction of the so-called "blowup modes" in neutron-multiplying media,
the verification of neutron moderation theories and so on. In this paper we
describe a method of GEANT4-based Monte Carlo calculation of the neutron
spectrum evolution as well as the steady-state neutron spectrum in a system
containing a persistent neutron source.Comment: 18 pages, 10 figure
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