(%) = percentage by weight of element
Ay
=
0.046/hr
%
«= 0.266/hr
Ay
= 18/hr
The numbers 24.7 and 60.3 in the equation give added weight to the manganese and alu6
c
~ 4
.
—-
”
|
~~
2
$
w
8
|
S
@
c
3
O
|
—
3
2
|
|
,
'
2
3
L
4
5
6
r7
8
9
W
Spectrum Change, X(r)
Figure 1.2 Corrections for variations in neutron spectrum.
minum relative to sodium on the basis of capture cross section, half-lives, atomic
weights, and gamma energies per disintegration
.
Then, for some other slant range, r,
Ip = ¥(r)Tp, he (F17)/200
mere Y(r) 2 1.
(1.8)
The factor Y(r) accounts for the effect of a spectrum whichis softer
an the equilibrium Spectrum.
Y(r) is a function of X(r) where
(rng) r
(r—1r,)/200
X(r) = ——VE_
1
(Mo )r,
(1-9)
ihe factor X(r) is the ratio of the surface thermal-neutron density
actually measured
? predicted for slant range, r, to that which would exist at r if the
equilibrium spec-
tr um obtained between r and
r;.
neutrons below the surfac
e,
Because of the importance of bui
ld-up of thermal
13