Why are only some particles fissionable/fissile?

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Discussion Overview

The discussion revolves around the question of why only certain nuclei are fissionable or fissile, exploring the stability of nuclei in relation to the ratio of protons to neutrons. Participants delve into theoretical aspects, stability conditions, and specific behaviors of different isotopes, particularly uranium.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that the stability of a nucleus is influenced by the ratio of protons to neutrons, with a most stable configuration that varies with atomic size.
  • Others argue that while adding neutrons can increase stability up to a point, excess neutrons can lead to instability and fission.
  • A participant mentions that uranium undergoes a different decay process compared to lighter nuclei, specifically splitting in half, which raises questions about the nature of its fission.
  • There is a contention regarding the strong force and its relationship to neutron addition, with some asserting that adding neutrons can worsen stability if the nucleus is already neutron-rich.
  • Disagreements arise over the interpretation of decay processes and the specifics of nuclear structure, including the concept of proton and neutron shells.
  • Some participants challenge the validity of claims made about nuclear stability and decay, emphasizing the complexity and exceptions in nuclear physics.

Areas of Agreement / Disagreement

Participants do not reach consensus, with multiple competing views on the stability of nuclei, the effects of neutron addition, and the specific behaviors of uranium and other isotopes. The discussion remains unresolved with ongoing debates about theoretical interpretations.

Contextual Notes

Limitations include varying definitions of stability, the complexity of nuclear interactions, and the potential for misunderstandings regarding decay processes and nuclear structure theories.

  • #31
granpa said:
you got 2 8 18 32 50 right but it stops there and starts over. the next would be 52 then 58 68 82 100

So you've got 4 right with your numerology, 4 wrong, and miss 3. I don't find that particularly impressive.

granpa said:
but when my ideas are being so totally misrepresented what can I do?

You could restrict your answers to mainstream physics and not bring your pet theories into it.
 
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  • #32
Uranium does not split in half when it fissions. The fission products have a spectra which correspond to two peaks, e.g. Ce-133 and Tc-99.
 
  • #33
http://en.wikipedia.org/wiki/Spontaneous_fission

But spontanous fission rate of Uranium is still very low compared to its other decay modes. So one has to specify I guess, so OP understands the entire picture.

It is also ambigous what the OP means by "Why are only some particles fissionable/fissile" but I suggest he is referring to why only some nuclei can be used in fission power plants - not why some nuclei undergo spontaneous fission.

Now if you bring up your own pet theories again, here or in superconductivity, you will run into trouble. Why can't you accept and follow the rules of this forum? If not, then why are you here?

Would you, when presenting your results in an article, say "nature occasionally has exceptions"? Totally non-serious...
 
  • #34
I still believe it is more illuminating to consider alpha decay as simply a form of spontaneous fission. The underlying physics is the same - you just have a very asymmetric split. Many nuclei only have this mode, some, like U-235, have others.
 

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