ORNL-1771 - Oak Ridge National Laboratory

form in terms of the Spence functions. A plot of
/(h/D) has been made (Fig. 11.1) by using the re-
sults of ORACLE computations. A report that
6
gives details of the calculation is being prepared.
Formulas for Multiple Scattering in Uniform Medium
0.2
0.f
...............
.
F. H. Murray
Method for Anisotropic Source and Scattering.
The Fourier analysis can be applied to multiple
scattering in such a manner as to lead to explicit
UNCL ASS1 FI E D
ORNL - 1.R -0WG 2645
INTENSITY NORMALIZED TO 1 AT INFINITY
-.I .................
0 1 .O 2 .0 30 4 .O
2 h/D
Fig. 11.1. Variation of Radiation fnknsity with
Altitude for a Constant Source-Detector Separation
Distance.
3
PERlOD ENDING SEPTEMBER 70, 1954
formulas, similar to some derived by Wigner’ but
which do net require a knowledge of group theory
for their application. Here the scattering law is
represented by a general formula, S(Zo, 2) dw, do,
for the probability that a particle arriving within a
-*
unit volume at P and moving in a direction W,
within the solid angle duo will be scattered into
the solid angle do in the direction Z.
Let Q and P be the points (xo,yo,zQ) and (x,y,z),
Fig. 11.2, and let f,(Q,Z,) do, dvQ be the number
of particles which have suffered their mth collision
in the volume element dVg = dx, dy, dzQ ond
emerged in the solid angle doo with a direction Go.
If the next collision occurs in a volume element
dV, and if n is the total cross section, the number
6J. E.
Neutrons
Detect or),
Faulkner, Single Isotropic Air Scattering of
in the Presence of tbe Ground (Unshielded
ORNL CF-568-96 (to be issued).
’E. P. Wigner, Phys. Rev. 94, 17 (1954).
UNCLASSIFIED
ORhL- LR -0WF ?646
Fig. 11.2. Geometry for Multiple Scattering Cal-
culation.
159