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Author Topic: Iron NMR  (Read 1201 times)
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Posts: 208
Nearly done with my design. Spherics said the tetra needed to be pulsed at a harmonic of iron's NMR. He also stated that the tetra deliberately requires "high megahertz square pulses". For the love of God the next time someone has some information, a little clarity would solve this completely. What is the frequency target?

With no upper target I'm going to have to assume a very high frequency. 50mhz is about the best I can do, with serious design headaches. Mosfets, even if mosfets, just cannot turn on and off must faster than 20ns, which is the limiting factor.
   

Group: Tinkerer
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Posts: 3948
tExB=qr
He later said that you can add a magnetic field around the entire tetra device (i.e. a solenoid coil) and operate at frequencies down to 3kHz
   
Jr. Member
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Posts: 59
Quote
iron's NMR

Long ago, I carried out an experiment with a ferrite rod from a radio receiver.
I wound 2 coils on a ferrite rod, each with 2 turns.
I installed a shielding partition between the coils so that only the ferrite rod passed through.
One of the coils was supplied with the generator output signal from the Frequency Response Analyzer, the opposite coil was connected to the input of the Frequency Response Analyzer 1 - 1000 MHz.
The impedance of the coils was matched as closely as possible to the output and input impedance of the Frequency Response Analyzer.

Interesting signal transmission maxima were observed somewhere between 60 MHz and 120 MHz. This happened when a neodymium magnet was brought to the end of the rod.
I can’t find more accurate information now, a lot of time has passed.
I haven't found any practical use for this. All this is in the region of very weak signals.
   

Group: Professor
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Posts: 1876
Found these papers on Iron NMR on my computer.

Smudge
   
Jr. Member
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Posts: 59
Simple Nuclear Quadrupole Resonance (MRI without magnets):

https://www.youtube.com/watch?v=JO_EHceV9sk
   
Group: Experimentalist
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Posts: 2023
...
Interesting signal transmission maxima were observed somewhere between 60 MHz and 120 MHz. This happened when a neodymium magnet was brought to the end of the rod.
...

Ferrites in radio receivers are made for the 150 KHz -> 1700 KHz AM bands. Above 2 MHz they have a lot of losses. Between 60 and 120 MHz, not only are there losses, but the high inductance doesn't allow for high current.
A neodymium magnet easily saturates these ferrites, which considerably reduces permeability, favoring higher frequencies, which explains the better coupling.


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"Open your mind, but not like a trash bin"
   
Jr. Member
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Posts: 59
This iron NMR effect is at a very low signal level relative to the excitation signal level. See the electrical diagram and explanation in the video linked above.

What surprised me was that experimenters claim that when a magnetic field is applied, the frequency decreases.
Yes, maybe there was a transmission in my experiment, but it looked like a mountain in the amplitude-frequency response.
Coil resonances were eliminated by high impedance of the signal source and receiver.
For a correct experiment, you need pure iron powder and not ferrite, which contains other elements.
   
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