|WikiProject Elements / Isotopes||(Rated C-class, Low-importance)|
- 1 DoD robot
- 2 Renaming proposal
- 3 Requested move
- 4 Use in RTGs
- 5 New paragraphs
- 6 kill one generation of humans ?
- 7 Dr. Natural
- 8 Another accident - April 2010
- 9 Cobalt-60 synthesis
- 10 Fe + neutron = Co?
- 11 Reference needed for reason for lack of naturally occurring Co-60
- 12 lifetime and decay energy
DoD robot ends Cobalt-60 nightmare: http://www.physorg.com/news9093.html
The specific activity of an isotope is 1/(atomic mass) * avogadro's number * the radioactive decay constant. For Co-60, this is approximately 1100 Ci/g. The quote without reference of ~50 Ci/g is wrong by over a factor of 20.
On the note of half-life. The half-life from KAERI, http://atom.kaeri.re.kr/ton/, is 1925.1 days. If calculated by 366 day year (leap year) the half-life is 5.26 yrs, while calculated by standard 365 days the half-life is 5.27 yrs. —Preceding unsigned comment added by Ssmeelink (talk • contribs) 18:45, 1 November 2008 (UTC)
I don't know what kind of math you've done in the past but when performing these kinds of calculations you don't assume leap year or not, you use 365.25 days/year. This is a basic premise in radiation physics. — Preceding unsigned comment added by 188.8.131.52 (talk) 01:32, 10 April 2012 (UTC)
If Co-60 is used in RTGs, I am certainly unaware of it, and it seems very unlikely. Manufacturers of RTGs specifically avoid radioisotopes that dissipate most of their decay energy via gamma-ray emission, particularly emission of high-energy gammas -- of which Co-60 is an excellent example. Anybody got a reference for this? If it can't be documented, I'm going to remove that throwaway mention. -- Bill-on-the-Hill (talk) 20:40, 25 February 2009 (UTC)
- Agreed. I can find no evidence of Co-60 ever having been used in an RTG. Removing it. Kolbasz (talk) 16:40, 16 April 2012 (UTC)
After deletion of the German article de:Cobalt-60 (there is the opinion that isotopic articles are superficial) I did my best to save its content here. Some parts may be found here: . Tubas-en (talk)+
kill one generation of humans ?
What does "kill one generation of humans" mean in this sentence. Would the author mind to add some informations. "[sic] ... is irradiated by neutron radiation from the fission process and transmuted to 60Co, has the power to kill one generation of humans." --Mandor (talk) 15:24, 16 March 2009 (UTC)
- T1/2 is around 5a. After 30a there is only 1/10 Co60 left -- and the polluted area might be repopulated. Please feel free to remove the sentence or to replace it by a better one. Tubas-en (talk) 17:51, 27 March 2009 (UTC)
- I can't seem to find who actually found the isotope in the beginning: it also tends to be great teams of scientists who find elements/isotopes nowadays, so great arguments have been sparked over who made which element (see the element naming controversy for elements 104-109). Since the isotope can be made by irradiation of natural cobalt, my best guess would be that some group decided to put natural cobalt in a nuclear reactor to see what would happen, and they got Co-60 as a result. The person who first came up with the idea for Co-60 therapy was Harold Johns, according to nature.com . Hope this helps! —Preceding unsigned comment added by 184.108.40.206 (talk) 05:59, 12 March 2011 (UTC)
Another accident - April 2010
Yes, there's been another accident, this time in India. Not notable, merely recent. We also don't report every airplane crash in the article for that type of airplane. -- SEWilco (talk) 22:15, 16 April 2010 (UTC)
Fe + neutron = Co?
((helpme)) There must be something wrong with the equation in the lead. A neutron cannot change a 59Fe nucleus into a 60Co (omitting the subscripted numbers, as all Fe nuclei have the "26" subscript anyway, and Co nuclei have 27)
The text in the lead says that the "radioisotope" 59Co is the starting point rather than 60Co, but that does not quite add up either. 59Co is stable.
A proton would add up well: 59Fe + p = 60Co = 60Ni + e- + gamma.
Reference needed for reason for lack of naturally occurring Co-60
On April 10, 2012, an anonymous editor made two edits saying in the comments that Co-60's short half-life is not the reason it cannot be found naturally. It is, of course, common sense that none of the Co-60 generated by stellar nucleosynthesis can be found on earth because it all decayed away within a few centuries of the earth's formation, but common sense is not a reference.
Before I enter an edit war with this extremely opinionated editor, I'd like to be armed with a reference. I'll check my elementary astrophysics textbooks for something applicable. If anyone else has a reference on hand already, please let me know. Thanks. Rwflammang (talk) 00:52, 11 April 2012 (UTC)
- Those edits were by me. It's not just common sense, it's physics and grammar. You will not find a reference supporting the verbage the way it was prior to my changes. Talk to any physicist, they will reassure you that my edit was for the best. If you want to add a tidbit in there about how it was earth once upon a time then do that and include a ref... but it shouldn't be part of the opening line about this isotope and it shouldn't be repeated again later in the article. Add it in the "occurrence" section, but again...be sure to include a solid reference and take care with your grammar, those are key to some of my favorite articles on this site so I'd like to protect that.
- Well then, let's find some better verbage. (Not that the old verbage violated common sense or physics or even grammar.) As the article primordial nuclide explains quite handily, if Co-60 had a long enough half life, then some of it would have survived un-transmuted to this day. Surely some Co-60 is made cosmogenically, but apparently not at a fast enough rate to overcome its inherent radioactivity. Since the radioactivity of a nuclide is inversely proportional to its half life, then it makes sense to say that cosmogenic Co-60 is not found in nature due to its short half-life. You get the point.
- Your edit comments stated that, Previously stated that "due to half-life not found in nature" this is absolutely incorrect. It's not found in nature because it's synthetic, half life and being found in nature have no relation to one another, and, Same reason as previous edit, citing "short half life" as the reason for no natural occurrence is nonsensical and absolutely incorrect. Perhaps you can explain how it is possible that either of these edit comments is true. Talk to any physicist ([silly insult against high school teachers omitted]); he will reassure you that it can't be. Rwflammang (talk) 01:02, 24 April 2012 (UTC)
- The "half-life not found in nature" part is bad grammar.
- OTOH, "half life and being found in nature have no relation to one another" isn't even remotely true. There are factors other than half-life, e.g. if it's in the decay chain of some abundant isotope (so that it is generated on Earth), so one must be careful about the wording as "not found in nature". I propose "nothing of the primordial nuclide has survived" instead, to make clearer that we are talking about the amount generated by the supernova causing the solar system to form. - ¡Ouch! (hurt me / more pain) 09:11, 10 May 2012 (UTC)
lifetime and decay energy
"The short lifetime contributes further to the high decay energy."