Radiofrequency Pulse

Abstract

We are now ready to begin part two of “MRR”- the Radiofrequency pulse (or “RF pulse”). Remember from the first chapter that when we send an electric current through a wire, we create an electromagnetic field. That is, we have both an electrical field and a magnetic field at the same time, which means that either a charged particle or a “magnetizable” substance would experience a force when placed in this region. Now if we make that current an alternating current, then at any spatial point in the field, the strength of the field will be varying in time. This means that the force that either a charged particle or a magnetizable substance would experience will vary in time from a maximum in one direction to a maximum in the opposite direction. It turns out that this variation in time can be mathematically described with a simple sine or cosine function.