
486 Nuclear Forensic Analysis
small impurities of Sr and Ra in BaFe
12
O
19
are not surprising, and the
226
Ra assay
a
nomaly
r
esulted
f
rom
t
he
a
symmetric
lo
ading
of f
errite
a
t
t
he
t
op
of t
he
b
illet.
Because
o
f
t
he
c
oncerted
e
ffort
t
o
p
lace
m
agnetic
o
bjects
w
ithin
t
he
i
nterior,
m
agnetometry
w
as
a
lso
c
onducted
o
n
t
he
i
tem.
F
or
c
ontext,
b
ackground
me
asure-
ments
o
f
t
he
m
agnetic
eld
at
t
he
s
urface
o
f
t
he
e
arth
g
ive
a
r
ange
o
f
v
alues
o
ver
approximately ±0.5 gauss. At the top, external surface of the billet, center-to-edge
m
agnetometer
me
asurements
v
aried
f
rom
8
0
t
o
−
10
G
.
T
he
i
nterior
(
without
t
he
s
peaker
d
rivers,
b
ut
w
ith
t
he
f
errite)
r
egistered
~
−7