On Wed, 30 Oct 2002, Tom Hazlett wrote:NOT NECESSARILY> Radsafers,
> Can anyone provide a reference that provides information on the relative
> intensity of the gamma rays emitted by a chain of isotopes that is in
> equilibrium?The decay rate for all members of the chain is equal to the decay
rate of the parent nucleus for the chain.
There are 3 general cases:
let K1 = decay constant of parent, A1e = equilibrium activity of parent
K2 = decay constant of daughter, A2e = equilibrium
activity of daughter
(Assume no branching.)
(1) transient equilibrium: K2 > K1, i.e. the parent is longer
lived than the daughter: Then: A2e = [K2/(K2 - K1)]*A1e
i.e., A2e > A1e
(2) secular equilibrium: K2 >> K1, really a special case of transient
equilibrium:
Then: A2e = A1e
(3) K2 < K1: no equilibrium
It gets more complicated if there's branching.
The opinions expressed are strictly mine.
It's not about dose, it's about trust.
Curies forever.
Bill Lipton
liptonw@dteenergy.com