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Physics
Physics
Problem
For a decay chain
X
→
Y
→
X \to Y \to
X
→
Y
→
stable product with decay constants
λ
1
\lambda_1
λ
1
(parent) and
λ
2
\lambda_2
λ
2
(daughter), prove that the time
t
max
t_{\!\max}
t
m
a
x
at which the activity of
Y
Y
Y
is maximum is given by
t
max
=
1
λ
2
−
λ
1
ln
(
λ
2
λ
1
)
,
(
λ
2
>
λ
1
)
.
t_{\!\max}=\frac{1}{\lambda_2-\lambda_1}\,\ln\left(\frac{\lambda_2}{\lambda_1}\right), \quad (\lambda_2>\lambda_1).
t
m
a
x
=
λ
2
−
λ
1
1
ln
(
λ
1
λ
2
)
,
(
λ
2
>
λ
1
)
.
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