Talk:Nuclear magnetic resonance/Catalogs/Magnetic nuclei
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- all atoms whose numbers of protons and numbers of neutroms are both even will not be magnetically active OR
- all atoms whose numbers of protons and numbers of neutroms are both not even will be magnetically active
I think the second tells you which elements will show up in NMR/MRI the top line tells you which will not show up - readers might get confused Robert Tito | Talk 16:49, 18 October 2007 (CDT)
I agree and will on it later. As it now stands, the sentence following it seems to be talking about the even/even when I am talking about the magnetically active ones. Got to fly now.
Also, the list is not complete, and only lists the common isotopes, not crazy short-lived atom smasher created ones.
David E. Volk 17:24, 18 October 2007 (CDT)
magnets
magnets used for NMR spectra are really strong (I have used magnets up to 60 Gauss) and cooled down (nitrogen most of the time) but superconductivity played no part to create these spectra. Only good channel analyzers and patience - many spectra took the best part of 72 hours to get a signal above the noise level. Robert Tito | Talk 17:17, 18 October 2007 (CDT)
It is the superconducting coils that allows for extremely large currents ( say 200 Amps or more)to last for years in a circular loop, which IS the magnetic field (Faraday effect). They actually all have a liquid Helium bath in the center, surrounded by a liquid N2 bath. N2 is filled every week or two, helium every 6-8 weeks. I don't recall the Gauss conversion, our magnets are about 17-20 Telsa (or 600, 750 and 800 MHz proton frequency).
- most materials at the T(He) are not superconductive but rather extremely well conducting. To get real way down you need hydrogen - but thats beside the general point: it needs being a very strong magnetic field, irrespective how that's produced. Next we get patients needing an MRI scan worried about the liquid nitrogen/helium and what it can do to them :). I will delete the reference to cuperconductive for ease of reading and the people that know about the topic know how thats produced. Robert Tito | Talk 17:43, 18 October 2007 (CDT)