Slow neutron distribution in a temperature gradient

Journal Article · Sun Dec 01 00:00:00 EST 1985 · Nucl. Sci. Eng.; (United States)

OSTI ID:5707118

Molinari, V G; Pollachini, L

A set of equations that describes the diffusion of thermal neutrons is obtained from the energy-dependent Boltzmann equation. These equations are analogous to the phenomenological laws of the thermodynamic theory of irreversible processes and show, for instance, that as a temperatur gradient produces a neutron current (Soret effect), a density gradient yields an energy flow (Dufour effect). The method is applied to the ''two-temperature problem'' in order to gain better insight into the thermal diffusion phenomenon. The thermal diffusion of neutrons is shown to strongly depend on the scattering law of the two media where neutrons diffuse, and it is determined that some of the conclusions previously obtained are valid only for the case of a heavy gas moderator with the scat tering cross section independent of the energy.

• Research Organization: Laboratorio di Ingegneria Nucleare dell'Universita di Bologna, Bologna
• OSTI ID: 5707118
• Journal Information: Nucl. Sci. Eng.; (United States), Vol. 91:4
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
SLOW NEUTRONS
THERMAL DIFFUSION
THERMAL NEUTRONS
BOLTZMANN EQUATION
COMPUTERIZED SIMULATION
CROSS SECTIONS
DISTRIBUTION
IRREVERSIBLE PROCESSES
NEUTRON DENSITY
SCATTERING
TEMPERATURE EFFECTS
TEMPERATURE GRADIENTS
THERMODYNAMICS
BARYONS
DIFFERENTIAL EQUATIONS
DIFFUSION
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
HADRONS
NEUTRONS
NUCLEONS
PARTIAL DIFFERENTIAL EQUATIONS
SIMULATION
654003* - Radiation & Shielding Physics- Neutron Interactions with Matter