Uncovering Half-Life Data for Odd Isotopes: A Search for Fission Products

In summary: I think I found it for 85-Se-m1, but I'm not sure about the other two. In summary, the Sigma database at Brookhaven lists seven isotopes as fission products for which I can't find half-life data. I've tried nea6287-JEFF-20-1, the NuDat_2 web site, Nuclear Wallet Cards and Wikipedia. Anybody have any other ideas?
  • #1
Moniz_not_Ernie
21
0
The Sigma database at Brookhaven lists seven isotopes as fission products for which I can't find half-life data. I've tried nea6287-JEFF-20-1, the NuDat_2 web site, Nuclear Wallet Cards and Wikipedia. Anybody have any other ideas?
The isotopes are
74-As-m1
85-Se-m1
86-Br-m1
109-Ru-m1
109-Rh-m1
143-Xe-m1
162-Tb-m1
 
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  • #3
Ooh, so close. Got the first one on the list, then went 0 for 6.

Thanks.
 
  • #4
You may want to check out these databases. http://www.nndc.bnl.gov/endf/b7.1/lists/dec-ENDF-B-VII.1.endf.listis a list of all the isotopes in the ENDF/B-VII.1 decay sublibrary. A quick look shows it has at least some of the isotopes. It doesn't say anything about meta-stable states for the ones I looked at so hopefully you mean m1 is the ground state instead of first excited state.
 
  • #5
Sorry. I do mean the first excited state. None of the isotopes on my list show up on the list you provided.
These aren't exactly rare fission products. The max yield for 109-Ru-m1 is over 1%, albeit for 142-Am-m1 as the fuel. For 85-Se-m1 it's ~0.5% for 233-U and 235-U. I expect they aren't much of a problem in the waste stream because of short half-lives. I'll mention them as a caveat in my assumptions.

Thanks, though.
 
  • #6
Moniz_not_Ernie said:
The Sigma database at Brookhaven lists seven isotopes as fission products for which I can't find half-life data. I've tried nea6287-JEFF-20-1, the NuDat_2 web site, Nuclear Wallet Cards and Wikipedia. Anybody have any other ideas?
The isotopes are
74-As-m1
85-Se-m1
86-Br-m1
109-Ru-m1
109-Rh-m1
143-Xe-m1
162-Tb-m1
http://atom.kaeri.re.kr/ton/
Did you look here? I got the results for all (I am not sure what you mean by m1).
I got for the particular isotopes: As 17.77 days, Se 31.7 s, Br 55.1 s, Ru 34.5 s, Rh 80 s, Xe 0.30 s, Tb 7.60 min.
 
  • #7
To mathman, re http://atom.kaeri.re.kr/ton/
(This forum doesn't indent enough!)
Yes I visited the Korean site, twice. On my second visit I followed one reference URL back to a UK paper on PDF at Brookhaven. A bit roundabout, but very worldly. The PDF topic is not really half-lives, but they use them to describe the excited states. The PDF doesn't label them m1, m2, etc. I got the 74-As-m1 half-life from the Korean site, then 109-Ru-m1 from the PDF. Four more to go.
The numbers you gave above are for the ground state. I'm looking for the first excited state (-m1).
 

What is an isotope?

An isotope is a variation of an element that has the same number of protons, but a different number of neutrons in its nucleus.

What is half-life?

Half-life is the amount of time it takes for half of the atoms of a radioactive substance to decay into a different element.

Why do isotopes have different half-lives?

Isotopes have different half-lives because they have different amounts of neutrons, which affects the stability of the nucleus and the rate of decay.

How is odd isotope half-life calculated?

Odd isotope half-life is calculated by dividing the natural logarithm of 2 by the decay constant, which is determined by the type of radioactive decay that the isotope undergoes.

What is an example of an isotope with a long half-life?

Carbon-14 is an example of an isotope with a long half-life of approximately 5,730 years. This is why it is commonly used in radiocarbon dating to determine the age of organic materials.

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