If you have Suns Java plug-in installed for your browser, an educational magnetic resonance Java Applet may have appeared above. If not, it is free, easy and safe to install Java using the pop-up installer (if this appeared in your browser) or by downloading Java from Sun Microsystems homepage. The applet was made for use in educational contexts. Initially, it is useful just to experiment with the applet to get a feel of the system components, and maybe discover magnetic resonance for yourself.

A simple group work exercise relying on the simulator, and corresponding introductory slides are provided as inspiration. A high school level MR exercise is further available in Danish ("lærervejledning til gymnasie-øvelse i kemi/fysik vedrørende MR-skanning og NMR"). It involves questions like the following:

• Determine how the needles natural oscillation frequency (the resonance frequency) depends on the B0 field created by the strong magnet.
• Demonstrate how a magnetic needle in a strong magnetic field can be made to oscillate significantly with the help of a weak, perpendicular magnetic field. This is used in NMR and in Magnetic Resonance Imaging (MRI) to get signal from magnetized tissues inside the body, since oscillating compass needles (magnetic dipoles) emit radio waves.
• Determine how the oscillation frequency and amplitude of the needle depends on the frequency and amplitude of the B1 field created by the weaker magnet. For example, the amplitude response in steady state of the needle can be plotted against the driving frequency.
• Show the signal variation in a pulse-acquire experiment, where transmission of radio waves (oscillation of the weak magnet) is interleaved with measuring periods.

• The Java Compass without any text..
• A zip-file with all documentation and all files necessary for running the Java Compass offline.
  Just unpack and point your browser to file://<path>/JavaCompass/index.html.