A general overview of nuclear fission is presented. The probability of fission is described based on developed models including the liquid drop model and shell corrections. Discussion on spontaneous fission and fissioning isomers is given. The transition nucleus and fission product distributions are discussed. The total kinetic energy, mass distribution, and charge distribution during fission are presented. Changes in fission product distribution with parent properties are introduced. Delayed neutrons from fission and their role in reactors are given. Proton induced fission is introduced.
On Question 3, for the fission of U-235, do we assume no neutrons are being emitted during the reaction?
ReplyDeleteWe're given both products for the first one and the results are consistent with no neutron ejection. I just went with that.
DeleteThat is the way I would do it.
DeleteI've heard about the damage neutrons can cause to reactor materials but never an explanation of how this relates back to the fundamentals of the fission process. Is the swelling and creep just on a microscopic scale or can it be observed on the macroscopic scale as well?
ReplyDeleteYou can visually see the damage. An example is at: http://cmcsn.phys.washington.edu/book/export/html/507
ReplyDeleteI am sure you can find others.
How do reactor engineers/fuel designers account for this as they make the fuel rods?
Deletespacing, materials, understanding how the materials change with dose.
DeleteThank you for the link very helpful!
DeleteI have a question about number 2 on the quiz. I may just be misunderstanding the question. I believe you're asking about the graph and why the heavy elements are all in the same(ish) region while the lighter elements are fairly spread out.
ReplyDeleteThe slides go on to say that there is usually asymmetric mass splitting due to shell effects, magic numbers. If this is the answer to the question I need a little clarification on the magic numbers/shell effects and their role in the making of this graph. Do the magic numbers just affect the heavy elements and that's why they're so nicly grouped where as the lighter elements don't have magic numbers so they're spread out?
Any help would be appreciated I want to understand!
The lecture on the shell model should help this. If I want to have symmetric fission products I need to overcome the shell effect. This happens if one fissions a nucleus with an energetic particle. The energy is transferred to the nucleons and with sufficient energy they start to behave more like a Fermi gas; hence the model for an energetic nucleus.
DeleteThis lectures ties in really well with several of the others to form a more complete pictured of some ideas we've already been discussing.
ReplyDeletethanks for the comments!
DeleteAnswers to Fission PDF Quiz posted.
ReplyDeleteIt was interesting to make the connection between reaction diagrams from my college chemistry courses and the fission diagrams.
ReplyDeletethanks for the comment
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