218 Nuclear Forensic Analysis
minor, but the medium is effectively innite in extent; combined with the
l
ong
r
ange
o
f
n
eutrons
i
n
m
atter,
t
here
c
ould
b
e
s
ubstantial
i
sotope
p
roduc-
tion
i
nduced
i
n
m
inor
s
pecies
i
n
s
oil.
S
oil
i
s
e
xposed
t
o
a
s
ofter
n
eutron
s
pectrum
t
han
a
re
t
he
i
ntervening
s
tructural
m
aterials,
r
esulting
p
rincipally
i
n
(
n,γ)
p
roducts,
a
nd
i
t
i
s
r
easonable
t
o
a
ssume
t
hat
t
he
e
lemental
c
ompo-
sition
of soil is pseudo-homogeneous on the large scale. It should then be
p
ossible
t
o
ca
lculate
t
he
s
oil
c
ontribution
t
o
e
very
r
adionuclide
i
n
a
d
ebris
s
pecimen
f
rom
t
he
a
nalysis
o
f
t
he
e
lemental
c
omposition
o
f
t
he
m
atrix
a
nd
t
he
c
oncentrations
o
f
i
ndicator
n
uclides
t
hat
a
re
n
ot
l
ikely
p
roduced
i
n
t
he
d
evice from neutron reactions with t