I've been parsing JSON radioactive decay data from the IAEA, and am trying to make sure I understand the numbers.
Here is a simple example:
Decay α 100%
Type keV %
α 4198 79
γ 13.00 7.3
OK. If I have this data, and I want to know how to guess what kind of radiation is going to be released over time from a given amount of U-238, what can I conclude? My understanding: nearly 100% of the time it is going to have alpha decay, and I can probably (for my purposes) just ignore the spontaneous fission. Great. 79% of the time, that alpha will be in the form of a 4.198 MeV particle, and 21% of the time it will be 4.151 MeV.
OK, but what about the gammas? Will there be a 13 keV gamma only 7.3% of the time? Is that 7.3% of the time for every alpha decay or is it only related to one of the specific alphas? This is the sort of thing I'm confused about.
One more example that illustrates some of my confusion:
Decay β- 100%
Type keV %
β- 95.77 99.88
γ 1332.492 99.9826
OK, so 100% of the time, this decays via beta-minus. 99.88% of the time, that beta particle is going to be 95.77 keV, 0.12% of the time it is going to be 625.87 keV. The next bit is less clear to me: does this mean that 99.9% of the time, it will have a 1.3 MeV gamma, and that 99.85% of the time it will have a 1.2 MeV gamma? That is, if I were calculating the gamma output, for each decay I'd need to check both of these gammas?
I know there are lots of gammas I am not counting here, and I'm really fine with that (for my purposes, a rough count of the most prominent ones is fine), but I just want to check that I'm understanding this correctly.