# References for nuclear masses, mass deficits, decay rates and modes

Where can I find the base data for computing the energy release of nuclear decays and the spectra of the decay products?

My immediate need is to find the energy release by the beta decay of Thorium to Protactinum upon receiving a neutron:

$$\mathrm{Th}02 + n \to \mathrm{Th}03 \to \mathrm{Pa} 13 + e^- + \bar{\nu}$$

The estimated amount of energy released from Beta decay is roughly 1eV. Minus the neutrino loss, how much kinetic energy is released as heat?

• Hi ThriceBeau, and welcome to Physics Stack Exchange! This is a site for conceptual questions about physics, not to get the answer to homework-like questions. If you can edit your question to ask about the specific physics concept that is giving you trouble in solving this problem, I'll be happy to reopen it. See our FAQ and homework policy for more information. Commented Aug 6, 2012 at 7:37
• I did not realize this was homework-like. This is a professional question I've been unable to find the answer to. Commented Aug 6, 2012 at 7:49
• See ie.lbl.gov/toi/nuclide.asp?iZA=900231. The decay energy is 0.39MeV though the site doesn't give any info on the distribution of kinetic energies of the electron and neutrino. The isotopes project site is a mine of useful information. I'd like to claim credit for finding it, but in fact dmckee brought it to my intention in his answer to physics.stackexchange.com/questions/33053 Commented Aug 6, 2012 at 9:19
• You can usually do very well getting the energy distribution with a simple phase space calculation: just throw values randomly in the allowed phase space. Commented Aug 6, 2012 at 15:06
• @ThriceBeau After some consideration I've bashed this up a bit into a form which I think is more suitable for the site. The big remaining issue is that I was not quite sure what to do with things like "Th 02" which is not a shorthand that I'm familiar with. Perhaps you could elaborate? Commented Aug 6, 2012 at 16:28