Questions tagged [nuclear-isomers]
15 questions
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Have we found all stable nuclear isomers?
Nuclear isomers are metastable nuclear states, typically protected from decay by having very different angular momentum from the ground state. Some are very stable; my favorite $^{180m}$Ta has a half-life greater than $10^{15}$ years.
The ground…
Anders Sandberg
- 34,657
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How do we know that a nucleus is in its ground state?
I think this must be a silly question but I would like the opinion of some experts.
A nucleus in excited states usually decay very quickly by isomeric transition, with a half-life of around $10^{-12}$ to $10^{-9}$ seconds. But there are many cases…
Jianing Song
- 217
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Is it possible that there are undiscovered optical transitions in nuclei?
Recently there was big news that the optical transition in Thorium $229$ nuclei had been identified by laser excitation. The excitation energy is $8.355733554021(8)\,\mathrm{eV}$. According to the nuclear clock wiki page, the next lowest lying…
AXensen
- 8,778
4
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2 answers
By how much are various dibaryon states unbound?
It has been known for a long time that the deuteron is stable but the dineutron (nn) and diproton (pp) are not. Many textbooks comment on this, but all the ones I found so far do not give quantitative information, and I have not found it via the…
Andrew Steane
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Creation of nuclear isomers
As I understand it, if a nucleus is excited with energy exceeding its ground state, it releases energy via gamma radiation. An example would be technitium 99m, a medical tracer with a 6 hour half life and 140 keV gamma radiation. What are the…
Michael Luciuk
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Are there any nuclear isotopes with both chiral and non chiral nuclear isomers?
I seek a nuclear isotope where one nuclear isomer is chiral and the other not. Are there any. Can there be any?
David Jonsson
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How do nuclear physicists know if a particularly long-lived nuclear isomer actually exists? If it never seems to emit a gamma ray?
Some nuclear isomers (like tantalum-180m) have never even been observed to decay....
How do we know it is in an excited state then? That it actually absorbed some form of energy?
Can these includes be induced to decay and emit a gamma ray, even if…
Kurt Hikes
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Nontrivial color current moments in the nucleus
Is not clear that all color-related moments of nuclei would vanish. A previous answer on the subject suggests some of them are not forbidden by symmetries.
Additionally, some nuclear experiments suggests many nuclei deviate from spherical symmetry,…
UnkemptPanda
- 361
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Why does the doubly-magic nucleus tin-$132$ have such a short mean lifetime?
Why does the doubly-magic nucleus tin-$132$ have such a short mean lifetime? Only because it is far from valley of stability?
tbb
- 13
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Is it possible for there to exist metastable exotic atoms?
I've been quite fascinated with the invention and discovery of exotic atoms such as: positronium, and muonic hydrogen etc...
Now I know positronium has a longer than usual lifetime because it is in a metastable state. My question is a rather laymans…
Sidharth Ghoshal
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What is an "excited nuclear isomer"?
I have been making an excel spreadsheet of all nuclides with half-lifes 20 hours or longer. If you look on the any of Wikipedia's "Isotopes of [insert any found element here]" pages, you will see lists of all the known isotopes for a given element.…
Curious Layman
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Cm-244 metastable state
While searching for decay product information for Cm-244, I came across the UCSD Radionuclide Data Sheets, which lists the half life for the metastable isomer Cm-244 (34 ms), rather than the nuclear ground state (18.1 yrs), however the data sheet…
apogalacticon
- 111
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Neutron Dose Rate to Activity Calculation
This is a completely hypothetical question but say I have an unknown radioactive source inside a steel box, given the dimensions of the volumetric source and the container, the neutron dose rate 1m outside of the box, the density of the volumetric…
sp444cegirl
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Why can't high-level nuclear waste be disposed of by bombarding troublesome isotopes with neutrons, protons and gamma rays (photodisintegration)?
Why can't isotopes with long half-lives be radiated with free protons, neutron radiation and gamma rays (photodisintegration) in order to transmutate those isotopes into something either stable (or stable-ish, with extremely long half-lives) or…
Kurt Hikes
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Nucleosynthesis of tantalum-isomer $^{180{\rm m1}}{\rm Ta}$
How does nucleosynthesis explain the creation of tantalum-isomer $^{180{\rm m1}}{\rm Ta}$?
Or what is the best theory to explain the existence of this?
It must be noted that the tantalum-isotope $^{180}{\rm Ta}$ is not very stable; its half-life…
Jokela
- 2,517