Hi humhum,
I am reading the book where your first image came from [
E. Buxbaum,
Biophysical Chemistry of Proteins: An Introductionto Laboratory Methods,
DOI 10.1007/978-1-4419-7251-4 34,© Springer Science+Business Media, LLC 2011].
On page 306, they say this works in superconducting magnetic fields.
"...nuclei with j ≠ 0 have a magnetic moment uN and can orient themselves parallel or antiparallel to an external mag-netic field (with a strength B0 of several Tesla), similar to a compass needle in themagnetic field of the earth. External magnetic fields are generated in superconduc-tive coils (Nb-alloys), cooled by liquid helium. The sample, however, is insulated from the cryogenic fluid and usually kept at room temperature...
... With the magnetic field strength cur-rently available (several Tesla), this LARMOR-frequency is in the order of several100MHz (500MHz at 12T is typical for current instruments)".
The magnet image they show is not a super conducting magnet coil that is used in the NMR spectroscopy.
They show this simple horseshoe magnet only to show which direction the magnetic field is pointing.
But the magnetic field they require has a strength of several Teslas or more.
They are talking about 9-12 Tesla fields that are created with superconducting magnets to produce 100-500MHz NMR frequencies.
To give you an idea,
The magnets that are used for holding papers the side of a refrigerator usually have about 0.05 Tesla field strength.
But 1 Tesla minimum field for NMR.
1 Tesla is 20 million times stronger than the earth's field, and it will cause all ferrous things near to become stuck to the magnet so you will have a very hard time to remove them.
But 1 Tesla magnetic field is not good for high resolution identification of samples. It is usually used for MRI imaging.
You need stronger magnetic fields which are carefully controlled for homogeneity to perform NMR spectroscopy.
This makes me think sakis1 did not use the equipment in this article, because I do not think sakis1 has a magnetic field anywhere near even 1 Tesla on his locator.
Your second image shows a bar magnet and some coils and a sample.
Is this sample the treasure that sakis1 recovered?
Best wishes,
J_P