272 Nuclear Forensic Analysis
beyond the current supplied by collection of all primary ion pairs is explained by
t
he
f
ormation
o
f
s
econdary
i
on
p
airs,
m
ainly
a
s
a
r
esult
o
f
c
ollisional
p
rocesses
g
en-
erated
b
y
t
he
a
ccelerated
e
lectrons.
A
pproximately
3
0–40
e
V
o
f
e
nergy
m
ust
b
e
s
upplied
t
hrough
i
mpact
t
o
c
reate
a
s
econdary
i
on
p
air
i
n
m
ost
c
ounting
g
ases.
T
he
n
umber
o
f
i
on
p
airs
a
vailable
f
or
c
urrent
c
onduction
i
s
i
ncreased,
a
nd
t
his
p
rocess
is known as gas amplication. Because amplication applies to each ion pair indi-
vidually,
t
he
m
agnitude
o
f
t
he
i
nduced
c
urrent
i
s
s
till
p
roportional
t
o
t
he
n
umber
o
f
p
rimary
i
on
p
airs
f
ormed
i
n
t
he
g
as
b
y
t
he
i
ncident
r
adiation.
I
f
a
n
i
ncident
α
p
article
i
nduces
1
00
t
imes
m
ore
i
on
p
airs
t
han
d
oes
a
n
i
nciden ...