4 ms·
> power density is inversely proportional to half-life It's not that simple. The energy per event varies by orders of magnitude depending on the specific trans
by gnode 7y ago
> power density is inversely proportional to half-life
It's not that simple. The energy per event varies by orders of magnitude depending on the specific transition (even within given particle decays, the energy of the emitted particle varies), also the number of atoms per volume or mass varies depending on material.
- Robotbeat 7y agoClearly. However it IS a good approximation. For RTGs, we desire primarily alpha emitters as alpha particles are generally the easiest type of decay product to shield (the thin metal casing will stop all alpha particles). And common Alpha emitters such as Po-210, Am-241, Pu-238, and U-232 all have a decay energy of about 5-6MeV even though they differ in half life (and thus power density) by 3 orders of magnitude.
- gnode 7y agoThe approximation holds true for the heavy elements, with similar atomic mass. I wonder if the power density of any similar half-life lighter nuclei would be significantly greater, or whether the energy of decay reduces roughly proportionately with their mass.
- Robotbeat 7y agoAnd, of course, almost all alpha emitters are heavier elements: https://www.researchgate.net/profile/Adam_Woolsey2/publication/328224660/figure/fig1/AS:680541158383618@1539265064126/Chart-of-Nuclides-showing-different-types-of-radioactive-decay-2.ppm https://www.researchgate.net/profile/Adam_Woolsey2/publicati...