NMR and the uncertainty principle: How to and how not to interpret homogeneous line broadening and pulse nonselectivity. III. Uncertainty?

Abstract

AbstractFollowing the treatments presented in Parts I and II, I herein discuss in more detail the popular notion that the frequency of a monochromatic RF pulse as well as that of a monochromatic FID is “in effect” uncertain due to the (Heisenberg) Uncertainty Principle, which also manifests itself in the fact that the FT‐spectrum of these temporal entities is spread over a nonzero frequency band. In Part III, I continue my preliminary review of some further fundamental concepts, such as the Heisenberg and Fourier Uncertainty Principles, that are needed to understand whether or not the NMR linewidth and the RF excitation bandwidth have anything to do with “uncertainty”. The article then culminates in re‐addressing our Two NMR Problems in a more conscientious frame of mind by using a more refined formalism. The correct interpretation of these problems will be discussed in Part IV. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part A 32A: 302–325, 2008.