DNA 1240H-2
i.
=
a.
S<R, - Z cot a.
n
8)* + £4° }
Rese. 1 fe fs (1) = 2[Vi cot a -
R,-2 ,cotarns
1
+
5
R)-8,cota-8
2.
--——;
Velae
e rete,
S>R,-
ro+u,
2
sr arc cos
re+5°- (R, “2 cota)?
5 =
dr
17-10)
( 7.
Using similar procedures,
nek?
arn ey
S + (R,-23 cot a)
r2+ 2,?
et
re+2,
S- (R)-z,. cot a)
arc cos
r°+g2 . (Ry - 2 cot a)
or S
2
dar
(17-11)
3. Ry - Z cot a“S<«R. Equation 17-9 applies to ail terms in the
summation from 1 = 1 to the largest 1 such that S<R
cot a.
Equation 17-10 applies to all terms in the summation bronhhe smallest
i such that S>R, - fy cot Atoten.
(2)
“Shallow” Geometry
Coneider a hollowed-out truncated cone (Fig. 17-10) with outer
and inner radii R) and Ro, height 2, interior angle a between each face
and base, and a receiver in the plane of the base at a distance S from
the axis of the cone.
deep case.
Let the coordinate system be the same ae in the
Then, if the dose-rate ratio N for the solid truncated cone
of the deep case is N(Ry, 2, Q, S),
-
N= N(R), Z, a, S) - N (Roy 2, « - @ S)
for the hollow truncated cone.
.
NEST AVAILAGLE
17-54
(17-12)
}