Albedo analytical method for multi-scattered neutron flux calculation in cavity.

Abstract

A simple formula which describes multi-scattered neutron flux in a spherical cavity was derived based on the albedo concept. The formura treats a neutron source which has an arbitrary energy-angle distribution and is placed a t any point in the cavity. T h e derived formula was applied to the estimation of neutron fluxes in two cavities, i.e. a spherical concrete cell with a 14-MeV neutron source a t the center and the "YAYOI" reactor cavity with a pencil beam of reactor neutrons. The results of the analytical formula agreed very well with the reference data in the both problems. It was concluded that the formula is applicable to estimate the neutron fluxes in a spherical cell except for special cases that tangential source neutrons are incident to the cavity wall.

Comment on “Room scattered neutrons” [Med. Phys. 26, 206–207 (1999)]

“…As reviewed in detail by Shin et al, 4 neutron albedos are generally well fitted with a cosine function of the reflecting polar angle. Shin et al 4 further stated that a necessary condition for uniform neutron fluence rate distribution is cosinelike dependence.…”

“…Shin et al 4 further stated that a necessary condition for uniform neutron fluence rate distribution is cosinelike dependence. In a complementary vein Leimdorfer 5 stated that the wall scattered gamma energy fluence rate in a room of any shape surrounded by cosine-emitting walls can be proved to be constant and isotropic.…”

“…Yes, but only after making major simplifying assumptions including the neglect of any explicit azimuthal and incident angle albedo dependence. Shin et al 4 developed the following tractable relationship for single reflection wall current arising from a centrally located isotropic neutron source in a spherical cavity Jϭ sc /4. ͑5͒…”

Application of a Simple Evaluation Method for Gamma-Ray Streaming to Multi-Bent Ducts Taking Account of Only Components Passing through the Duct

“…(3) as expressed above, we give imaginary source intensity 81 at point P1 as, 81 = 1l"T~<p1 = (¼r c: r (;; r s, (4) and radiation flux </ >2 at point P2 as, = 4:l5 (if c~ r (: r (5) By analogy to the above, radiation flux </>n at the exit point of the n-th leg can be obtained as,…”

Improvement of a Simple Evaluation Method for Duct Streaming by Taking Account of the Deep Penetration Component

“…[1][2][3][4][5][6][7][8][9] But the desired degree of simplification cannot always be achieved in most of them, since enormous preparatory calculations are necessary to estimate the radiation shielding properties for using the formulae.…”