|WikiProject Physics||(Rated Start-class, Mid-importance)|
Made a few changes:
First I removed the sentence concerning the inability of alphas betas or gammas to induce activity. Photoactivation is possible, as well as, light particles activation. Proton activation for instance is a famous analytical technique.
I commented in the first paragraph, on the fact that the half life of the produced nucleus can be very short, but also very long.
I added a line in the first paragraph concerning the possibility to have particle emission after the capture of a neutron. This process would also lead to a possibly radioactive residual nucleus.
I changed the comment on neutron activation stating that it is the most sensitive method, and made it more neutral by writing "one of the most sensitive"
Made a small change in the two last sentences of the article, writing that the half life "may be short" and changing "Thus" into "In this sense" at the beginning of the last sentence.--Pgrouse 12:11, 9 October 2006 (UTC)
Removing suggested merges
I am removing the suggested merges to prompt gamma neutron activation analysis and neutron activation analysis. There has been no discussion about this for a while (ever?) and I think they are pretty clearly separate articles. This article is about the physical process, those articles are about an application of the phenomenon. -Cwenger (talk) 18:40, 17 July 2010 (UTC)
Beryllium 8 Fission
Sorry as I am not (yet) an expert on this matter, but wouldn't the addition of a neutron to the nucleus of the Be-9 atom cause it to become Be-10? Holding the equation on the article to be true am I correct in assuming that the acceptance of the neutron causes the ejection of two neutrons (as a result of the free neutron's high energy) and thus the creation of the Be-8 and subsequent spontaneous fission of the atom? If this could be clarified here as well as on the article (if possible) I would greatly appreciate it. Ham Radio 02:39, 21 March 2012 (UTC) — Preceding unsigned comment added by Ke5skw (talk • contribs)
Statistical analysis is not equal to activation analysis
I removed a bizarre link to an FBI case story, where statistical analysis of the results of neutron activation analysis (Comparative Bullet Lead Analysis) in evidence used in a case appeared to be trying to discredit NAA.
The case relied on a statistical analysis of a box of bullets analysed for metal composition by NAA. However, the NAA analysis was not in question. The problem appeared to be the faulty use of statistical analysis of the NAA results to fraudulently implicate a defendant.
This could only possibly be of the most marginal benefit in understanding NAA. In fact, it's far more likely someone added the link to either a) imply that NAA was faulty in one case, and thereby bring into question NAA generally (which is a FAIL right there), or, more likely, b) push some personal agenda about the case itself, or a personal belief that the scientific basis of NAA somehow led to the false imprisonment of an individual. Which is another fail.
Elements supporting neutron activation
"Some elements are very difficult to activate, because the capture of a neutron by the most common isotopes of those elements converts the atom into another heavier, but still stable isotope. The primary elements this is true for are hydrogen, helium, carbon, nitrogen, oxygen, neon, silicon, sulfur,[dubious ] titanium, chromium, iron and platinum,..."
Note the dubious and citation needed flags following sulfur. From the internal element's pages referenced, the following:
|Most common stable isotope(s) (abundance)||Next more weighty stable isotopes (Half lives)|
|hydrogen-1 (99.985%)||H-2 (stable), H-3 (8 days)|
|helium-4 (99.99983%)||He-5 (700e-24 sec))|
|carbon-12 (98.9%)||C-13 (stable), C-14 (5730 years)|
|nitrogen-14 (99.634%)||N-15 (stable), N-16 (7.13 sec)|
|oxygen-16 (99.76%)||O-17 (stable), O-18 (stable), O-19 (26.464 sec)|
|neon-20 (90.48%)||Ne-21 (stable), Ne-22 (stable), Ne-23 (37.24 sec)|
|neon-22 (9.25%)||Ne-23 (37.24 sec)|
|silicon-28 (92.23%)||Si-29 (4.67%, stable), Si-30(stable), Si-31 (153 years)|
|sulfur-32 (95.02%)||S-33 (stable), S-34 (stable), S-35 (87.32 day)|
|titanium-48 (73.8%)||Ti-49 (5.5%, stable), Ti-50 (5.4%, stable), Ti-51 (5.76 min)|
|chromium-52 (83.789%)||Cr-53 (9%, stable), Cr-54 (stable), Cr-55 (3.5 min)|
|chromium-50 (4.3459%)||Cr-51 (27.7d)|
|iron-56 (91.782%)||Fe-57 (stable), Fe-58 (stable), 59 (44.5 days)|
|iron-54 (5%)||Fe-55 (2.73 yr)|
|platinum-94, -95 (together 67% of Pt)||Pt-96 (stable, 22%), Pt-97 (19.89 hr)|
Helium is plainly not an absorber of neutrons. Of the rest, all can absorb at least one neutron and remain stable except for 9% of neon, 4.3% of chromium, 5% of iron, and 22% of platinum. So, I propose to reword the statement to read:
"Some elements are very difficult to activate, because the capture of a neutron by the most common isotopes of those elements converts the atom into another heavier, but still stable isotope. The primary elements this is true for are hydrogen, carbon, nitrogen, oxygen, silicon, sulfur and titanium. Some other elements are resistant for their most common atoms, but have significant minority isotopes present which can be activated by a single neutron capture: neon (5% activatable), chromium (4.3%), iron (5%), and platinum (22%), ...".
As for the no citation, all this data was gathered from the wiki pages internally referenced or their element isotope pages directly referenced from the element pages. SkoreKeep (talk) 23:24, 5 March 2014 (UTC)
- So, just so I get this straight, you removed a citation needed tag because...wiki "internal pages" make you think you know what you're talking about?
- If this was the first goof I've seen you make I'd let it slip, but I notice that I've encountered you before, particularly with your atrocious Enewetak atoll "summary table", a table that I had to spend considerable time fixing, while you - and I paraquote from the talk page - "ran off to do some other projects."
- You should really think about not editing at all man, until you learn that you must provide reliable sources! Your own WP:OR skimmed from Wikipedia internals pages does not even come close to WP:RS!
- As for sulfur, which you claim isn't activated. Phosphorus-32 can be generated synthetically by irradiation of sulfur-32 with moderately fast neutrons as shown in this nuclear equation:
- So yeah, sulfur is activated in practice!
- Are you sure you don't suffer from Dunning–Kruger effect, you don't demonstrate any degree of humility and have a disregard for providing reliable sources? If there is a definition that neutron activation HAS to excite the same element, and explicitly cannot be used to describe neutron absorption reactions that result in the transmutation of the element into a completely new but radioactive daughter element, then provide a reliable source that suggests that characterization. Until then, it's misleading to suggest sulfur can't be neutron activated, as I've detailed above.
- 184.108.40.206 (talk) 07:01, 7 March 2014 (UTC)
- Oh, I'm not all that evil. DK is certainly possible; by definition I wouldn't know, would I? I'll think about that. I do try to get things right though I don't always succeed; I know very few people for whom that doesn't hold. If that disqualifies me from editing, then I'll want a second opinion on that. I don't have a problem with someone pointing out something I wrote is wrong, but the invective that you seem so able deliver - it's pretty breathtaking.
- I built the table above to make a case. It appears that it is not the whole story, that there is at least one special case which supersedes in sulfur, and so despite being correct I was wrong. I'll admit that without rancor, and I'll fixed it, just as I fixed it yesterday. However, the data in the table above isn't in error, and it doesn't really make any difference whether that data was collected from Wikipedia or my CRC databook, or the Brookhaven labs webpages. The stability, half-lives and percentages of common occurrence aren't different in any of these; the exception would still be there, despite the data being correct. I would suggest that perhaps it would be more useful to have pointed out that there was an exception on the talk page (in addition to the flags and the one-liner edit summary) so I could have tried to look it up, or even to have edited a correction in yourself. What you wrote above in response to my talk page attempt at explanation was enlightening. I wish you had done it earlier rather than after. You are at least one exception beyond me, maybe way beyond me, and one wonders why you wouldn't make it a teaching experience.
- So, now I know there is an exception, and I can edit this one in and then go look and see if perhaps there are others, because that's what occurs to me. What percentage of neutron captures in sulfur result in a proton decay? Is it 10%, or 100%? See, you can teach, in spite of yourself. :) SkoreKeep (talk) 16:43, 7 March 2014 (UTC)
Orphaned references in Neutron activation
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in wikilinked articles. I have found content for some of Neutron activation's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.
Reference named "NUBASE":
- From Barium: Georges, Audi; Bersillon, O.; Blachot, J.; Wapstra, A.H. (2003). "The NUBASE Evaluation of Nuclear and Decay Properties". Nuclear Physics A (Atomic Mass Data Center) 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
- From Thorium: G. Audi; A. H. Wapstra; C. Thibault; J. Blachot & O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT⚡ 10:05, 7 April 2015 (UTC)