NMR experiment to find G-factors

[physicsjock]

Hey,

I did a small experiment to determine the electron, proton and fluorine nuclei g-factors using a teltron set up shown below. The experiment was set up to sweep the static magnetic field between 0 and 3.67 mT and to keep the frequency of the perpendicular high frequency field constant.

When using the electron probe and electron target sample, hollow cylindrical cores are placed between the scan coils and interface with pole face rings at the entrance to the sample chamber. The sample chamber is an enclosed box between the two scan coils where the sample sits in the electron probe.

With this set up I got really good resonance peaks with nothing unexpected.

Just out of curiosity i replaced the pole faced rings with pole faced discs and reran the experiment.

It produced these another peak at the end of the sweep which is roughly half the size of the main resonance peak. The best way to explain it would be, after the main resonance peak, there is about 10 ms of minimum, normal output, then towards the end of the sweep the output increases forming an almost linear increase until the magnetic field is maximum. The sweep ends then repeat.

This peak couldn't correspond to energy transitions because they are only half the size of the resonance peak, if it was an energy transition would the peaks be just as big as the main resonance peak?

Does anyone know what these peaks might be?

The only difference between the single resonance peak and the weird results is that I changed the volume of the cavity right?

I would have posted pictures up as well but the oscilloscope I used wasn't connecting properly to any printers.

 

[AndyW]

Hello,

Thank you for sharing your experiment and results with us. It is always exciting to see fellow scientists conducting their own experiments and discovering new things.

From your description, it seems like the additional peak you observed could be due to a phenomenon known as "double resonance". This occurs when there are two different resonant frequencies present in the system, resulting in two distinct peaks in the output. In your case, the main resonance peak could be due to the electron probe and target sample, while the additional peak could be due to the pole faced discs interacting with the system.

To confirm this, I would suggest conducting further experiments with different configurations and samples to see if the additional peak persists. Additionally, you could also try adjusting the frequency of the perpendicular high frequency field to see if it affects the size or presence of the additional peak.

Regarding your question about energy transitions, it is possible for the peaks to be different sizes even if they correspond to energy transitions. This could be due to differences in the transition probabilities or the strength of the magnetic field.

I hope this helps in understanding the results of your experiment. Keep up the good work and keep exploring! If you have any further questions or updates on your experiment, please feel free to share them with us.



Scientist