Talk:Neutron capture

Light vs Heavy Elements and Neutron Capture

Concerning the capture of neutrons by heavier as compared to the lightest elements, the "Chart of nuclides showing thermal neutron capture cross section values" visually depicts this matter (I believe), but I think it would be valuable to expound on this in the narrative more so than it is. A geologist with a background in nuclear physics told me that it is only the heavier elements beginning with Na that readily capture neutrons. He worked in private industry bombarding various elements with neutrons and had much experience in this. The section "Capture cross section" states that, "the effective cross sectional area that an atom of that isotope presents to absorption... is a measure of the probability of neutron capture." It seems that it would help less technical readers if this article would explain this phenomenon in the narrative, in terms of which of the lightest elements are unlikely to capture neutrons. That geologist told me that they used carbon extensively, but only to slow down the neutrons. Thoughts? Bob Enyart, Denver KGOV radio host (talk) 17:01, 13 November 2015 (UTC)[reply]

It's almost a year later, and I still don't feel confident enough to make this suggested improvement myself. The geologist, PhD from Colorado's engineering School of Mines has again restated to me the particulars above. And I'm SURE this doesn't fall into the category of Original Research. This is just a request to make this more understandable, and explain in a way that more science-aware readers can understand what elements can more readily capture neutrons, and which cannot. Can anyone help with this? Please? :) Bob Enyart, Denver KGOV radio host (talk) 17:46, 13 September 2016 (UTC)[reply]

Well, boron is an old favorite for reactor control rods, and it isn't that heavy. It all depends on the neutron energy levels in the nucleus, which are more complicated than electron energy levels, and harder to predict. And then there is He3, which also likes neutrons. Gah4 (talk) 06:14, 22 April 2022 (UTC)[reply]

Chernobyl

I have only heard of neutron absorbers being used in reference to Chernobyl, perhaps a brief overview of how neutron absorbers might mitigate a nuclear disaster would be helpful. —Preceding unsigned comment added by 208.120.255.5 (talk) 08:11, 5 December 2010 (UTC) The first thrown though the hole at the roof of chernobyl plant have been 40t borone carbide B4C to stopp or slowing nuclear chain reaction using helicopters but B4C is just swimming upon UO2 better are more heavy absorbers like better absorbing HfB2 or HfC. Next was lead Pb against gamma rays but melting away not neccessary just adding sand is enough with 2-3m near gamma dense. — Preceding unsigned comment added by 91.10.83.201 (talk) 12:38, 7 March 2012 (UTC)[reply]

Assessment comments

I would like a brief, relatively non-technical description of why there is no need for a moderator in fission nuclear weapons and there is in reactors. —Preceding unsigned comment added by Grumpyoldgeek (talk • contribs) 01:20, 24 September 2010 (UTC)[reply]

I find this sentence rather confusing. "For example when natural gold (197Au) is irradiated by neutrons the isotope 198Au is formed in a highly excited state which then quickly decays to the ground state of 198Au by the emission of γ rays." As a general, non-specialist reader, this seems to me to be saying that 198Au decays to itself. Dawright12 (talk) 17:03, 17 October 2010 (UTC)[reply]

In response to the comment above me, I believe it's saying that 198Au in it's highly excited state decays to itself, only in the ground state of. —Preceding unsigned comment added by 67.188.16.35 (talk) 06:58, 20 October 2010 (UTC)[reply]

This edit request has been answered. Set the |answered= or |ans= parameter to no to reactivate your request.

in response to the comment by Dawright12: A nucleus in an excited state means a nucleus that has an energylevel that is too high. It will radiate this energy (by gamma radiation) so that it may become stable. 198Au ineeds decays to itself, but to itself in a stable state.

Not done: {{edit semi-protected}} is not required for edits to semi-protected, unprotected pages, or pending changes protected pages. --Bryce (talk | contribs) 11:23, 2 January 2012 (UTC)[reply]

Neutron capture therapy

An important application of neutron capture that could use a link in the See Also section, if not its own treatment in the article.

Neutron_capture_therapy_of_cancer

Thermochemical consequences

I`ve added a paragraph about thermochemical consequences of neutron capture.--213.233.84.84 (talk) 10:11, 6 October 2015 (UTC)[reply]

External links modified (February 2018)

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Nonradiative neutron capture

I see that the article does not specify whether the neutron capture can be radiative or nonradiative.--109.166.137.46 (talk) 18:06, 28 November 2019 (UTC)[reply]

Most often, you can't have a reaction with two things coming together to make one, and conserve both momentum and energy. Mostly that means radiative capture. Gah4 (talk) 14:34, 20 December 2021 (UTC)[reply]

resonance integral

It seems that resonance integral links here, and it is mentioned, but not so well explained. I might have thought it should have its own article. I am trying to figure this out related to another article. Gah4 (talk) 14:35, 20 December 2021 (UTC)[reply]

A Commons file used on this page or its Wikidata item has been nominated for deletion

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:

Chart of Nuclides - Thermal neutron capture cross sections.png

Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 04:39, 4 April 2023 (UTC)[reply]

Wrong

"Nuclei of masses greater than 56 cannot be formed by thermonuclear reactions (i.e., by nuclear fusion) but can be formed by neutron capture."

This sentence is obviously wrong. I think maybe what the original author meant was that inside (normal) stars fusion of such heavy atoms does not happen, as it is does not provide energy, but consumes it. When it happens the star stops being a star, as that fusion will not provide heat to counter the gravitational collapse, and you have a supernova... But during the initial supernova implosion *that fusion does happens.*

Really heavy atoms manufactured by mankind are usually created by having heavy atoms fusion with each others. Moscowium (115) was made by humans via fusion of Americum and Calcium, thus giving an a direct contradiction.

The text is guarded by a reference to a paper i can not read. But most likely if one actually reads that paper, it does not just flat out say its impossible, but just that it does not happen in normal stars during their lifespans. We should update this so it becomes more clear! · · · Omnissiahs hierophant (talk) 10:40, 12 July 2024 (UTC)[reply]

Update, this was fixed in [1] by Gah4. Thanks.