Lab Assignment: Nuclear Magnetic Resonance

In this lab you will explore nuclear magnetic resonance with the Teachsping Pulsed/CW NMR Spectrometer.

Part A. Find the Free Induction Decay in mineral oil

Before you begin you will need to familiarize yourself with the equipment by carefully reading the manual provided below. You are encouraged to read the theory and experimental apparatus description thourougly before you turn on the spectrometer. It may also be beneficial to read through and understand qualatatively how an oscilloscope works. For this lab you will be using the new Textronix oscilloscopes in the locked cabinet, the Tektronix DPB 2024B . I

Part B. Find the relaxation times T1 and T2 in your samples of mineral oil

The PS_NMR.pdf file linked below has a nice description on how to perform this measurement. Ask if you have questions.

The manual for the spectrometer is available PS2Lab-manual.pdf: Teachspin PS2-A NMR manual

Laboratory procedure:

1. Read the manual attached below before you start
2. Connect all coaxial cable not already connected. The manual describes how to do this. Most likely you'll just need to do connect the spectrometer to the oscilloscope.
3. Use the NMR probe to check that the spectrometer is properly calibrated. This part is described in the "Getting Started" section. PLEASE DO NOT adjust the capacitors until you've obtained the signal shown on page II-19 of the manual and you have consulted with me. If this calibration is not carried out properly it will be difficult to find FID signal and it is easy to do this incorrectly. Record the voltage and time sweep observed. Do they correspond with what you expect?
4. Now attempt to find the FID signal on page III-7 on the oscilloscope. Use the prepared mineral oil provided. Record the voltage and time sweep on the oscilloscope. Do you understand what these mean? Are they as expected for the sample at hand?
5. During the search for the FID signal play with the spectrometer settings and look through the questions on page III-7. Try to answers them as you progress through the experiment. At first they may not make sense but by the end of the experiment most of them should be clear. Don't worry about answering them on your report, unless you feel compeled to do so.
6. Make sure you record the oscilloscope output. The easiest way to do this is to take a photo of the scope screen with your phone. The new Tektronix scope also has a USB port you can use to record the output of the scope, in a supported image format.

Some useful links:

• You Tube video on Magnetic Resonance using earth-field NMR experiment. The technology employed is different but the discussion is, particularly the theoretical description is appropriate to the Teachspin device http://www.youtube.com/user/magritek
• This online book by Joseph P. Hornak, Ph.D. is something worthwhile to peruse http://www.cis.rit.edu/htbooks/nmr/inside.htm
• A nice simulation from the UF's Center for Safety, Simulation and Advanced Learning Technologies. It provides you with a better visual of how NMR works. You'll need an Adobe Shockwave so you ipad/iphone may not work and or you'll need to add it to you browser. It worked from me from explorer but not with chrome. http://vam.anest.ufl.edu/simulations/nuclearmagneticresonance.php

• PS2_Conceptual_Introduction_to_the_Experiment.pdf: Nice summary of the physics and measurement of T1 and T2 with the PS2-A.
• PS2_Manual_1.41.pdf: Revised Teachspin PS2-A manual. It superseeds the old manual and a great improvement.
• Pulsed_NMR.pdf: Document that features the PS1A experiment, a precurser to the one you will be using, but with an excellent and clear description of the physics, the experimental setup and measurment of two relaxation times T1 and T2. A good supplement to the new manual
• PS2_Aliasing_on_the_Digital_Oscilloscope_Rev_2.0.pdf: A note on scope usage that may be a worthwhile read.