Eric-- I did misunderstand what I thought you were saying.
I do agree with you that most people consider nuclear isomers to be excited energy states with a large differential energy above the ground state. I have always considered any excited nuclear state to be a nuclear isomer. I do not know what the elevated energy nuclear state which is due to spin energy as established during an NMR energy addition would be called. I think it fits the general definition of an excited state with a lifetime less than 10-9 sec., and, thus, it is not metastable from that standpoint. As you point out normal NMR states are not at a large energy differential, except in large magnetic fields. The larger the field, the greater the excited energy is above the ground state. I think that the rule is that the changes in spin angular momentum have to be prime number multiples of the h/2-pie quantum of angular momentum. The energy of the elevated state results from the change of the nuclear spin magnetic moment in the ambient B magnetic field. Bob Cook From: Eric Walker Sent: Sunday, January 17, 2016 10:20 AM To: vortex-l@eskimo.com Subject: Re: [Vo]:Re: Nuclear Isomers (2005 article in Nature) Hi Bob, On Sun, Jan 17, 2016 at 7:15 AM, Bob Cook <frobertc...@hotmail.com> wrote: I agree with your thought about the role of isomers in the natural abundance of elements. I think you accidentally mistook the quote I was quoting from Harry's article for something I myself said. I was asking for clarification of what they were saying. Isomers are what makes nuclear magnetic resonance (NMR) a valuable tool. The idea is that a nucleus is excited to an elevated “isomeric” energy state by a RESONANT radio frequency input energy in a magnetic field and then decays back to its initial “ground state'’ or some other ground state not the same as the original state. Forgive my ignorance -- when we talk about NMR, I think of polarization of nuclei with nonzero spin in an external field using radiowaves or microwaves. When I think of an isomer, I think of a nuclear isomer, in which the nucleons in a nucleus are in a configuration that lies keV or MeV above the ground state. I don't think radiowaves or microwaves can do anything to populate or depopulate these states; or am I mistaken? A question I have about the nuclear isomerism referred to in the opinion piece has to do with its potential utility. It seems like it would at best be good as a battery, or, possibly, a bomb. Eric
