Probability of U-235 fission happening

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    Fission Probability
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Discussion Overview

The discussion revolves around the probability of U-235 nuclear fission occurring, specifically addressing the reported percentages of ~82% for fission and ~18% for non-fission events. Participants seek to clarify the meaning of these percentages and the context in which they apply.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants inquire about the source of the ~82% and ~18% figures, questioning what these percentages represent.
  • One participant provides a link to a resource that may contain relevant information regarding U-235 fission probabilities.
  • Another participant suggests that the percentages might relate to the ratio of slow neutron fission cross-section to total slow neutron interactions, estimating it to be approximately 84%.
  • There is mention of other processes involved, such as elastic scattering and the production of U-236, which may influence the fission probabilities.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the interpretation of the percentages or the specific context they apply to, indicating that multiple views and uncertainties remain in the discussion.

Contextual Notes

Participants express uncertainty regarding the definitions and denominators used for the reported percentages, which may affect the interpretation of the data.

NewPhysi
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Where can I find information about the ~82% of U-235 nuclear fission happening and ~18% not happening?
 
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NewPhysi said:
Where can I find information about the ~82% of U-235 nuclear fission happening and ~18% not happening?

Where did you find those numbers? What do these percentages correspond? like 82% of what?
 
snorkack said:
One possible link:
https://wwwndc.jaea.go.jp/cgi-bin/Tab80WWW.cgi?lib=J40&iso=U235
What do you want to choose as denominator?

yea I figured that it was somewhat related to ## \dfrac{\sigma (\text{slow }n \text{ fission})}{\sigma (\text{slow }n \text{ total})} \approx 84 \%## the other important processes are just elastic scattering and production of U-236* which decays via gamma to U-236
 

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