
70 Nuclear Forensic Analysis
concentrations dened by their decay properties and the law of secular equilibrium
(
Equation
2
.5).
T
he
t
hree
s
eries
a
re
n
amed
t
he
u
ranium,
a
ctinium,
a
nd
t
horium
s
eries,
a
nd
t
hey
a
re
s
hown
i
n
F
igures
2
.17
t
hrough
2
.19,
r
espectively.
T
he
d
ecay
m
odes
o
f
t
he
i
ndividual
n
uclides
m
aking
u
p
t
he
d
ecay
s
eries
a
re
g
iven,
a
nd
t
heir
d
etailed
d
ecay
p
roperties
a
re
p
rovided,
i
n
T
able
2
.3.
T
he
u
ranium
s
eries
(
Figure
2
.17),
w
hich
b
egins
at
238
U and ends at stable
206
Pb, is also known as the (4n + 2) series because the mass
n
umbers
o
f
ea
ch
m
ember
o
f
t
he
d
ecay
c
hain
c
an
b
e
d
escribed
b
y
t
his
f
ormula,
w
ith
n
=
5
1–59.
I
t
i
s
n
oted
t
hat ...