EFFECTIVE BOUNDARY CONDITION AT THE PLANE SURFACE OF A PERIODIC LATTICE

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Nekotorye Vopr. Inzh. Fiz.

OSTI ID:4065388

Khromov, V V

The effectiveness of a planar lattice of neutron-absorbing rods in cutting off the active core was considered. It was essential to be able to calculate the greyness'' of such an array. As a model for study an infinite medium was chosen, which supponts a flux of monoenergetic neutrons. The absorbing material was disposed on the plane x = 0 in the form of long, thin strips, infinlte in the z-direction. Each strip was of width a'' and separated in the y-direction from its neighbors on either side by a length b'', thus giving a period T'' to the absorber lattice, where T = a + b. Each strip was considered to be black'' to incident neutrons. The general solutions of the diffusion equation were used in each half-space in combination with shadowing'' conditions for the transport of neutrons across the absorbing plane to obtain the effective transparency, C, of the absorber lattice. The diffusing medium itself was allowed to be either absorbing or non-absorbing for peutrons. Limiting cases are discussed and compared with results from the Vinera-Khopfa method. A table of numerical results for the effective extrapolation length into one half-space from the other is given as a function of the period T'' and the transparency C/sub o/'' (which depends on the ratio b/T). (TTT)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-015477
• OSTI ID: 4065388
• Journal Information: Nekotorye Vopr. Inzh. Fiz., Journal Name: Nekotorye Vopr. Inzh. Fiz. Vol. Vol: No. 4
• Country of Publication: Country unknown/Code not available
• Language: Russian

Related Subjects

ABSORPTION
BOUNDARY CONDITIONS
CONFIGURATION
DIFFUSION
ENERGY
EQUATIONS
EXTRAPOLATION LENGTH
MATHEMATICS
NEUTRON FLUX
NEUTRONS
NUMERICALS
REACTOR TECHNOLOGY
RODS
SURFACES
TABLES
TRANSPORT