Comparison of spin-lattice relaxation measurements made in the presence of strong radiation damping

The scientific literature contains reports of external magnetic fields affecting the fundamental properties and structure of water, including a report of the rotational motion of water molecules being slowed due to increased hydrogen bonding resulting from magnetic treatment. To investigate such a change in molecular motion, (1)H spin-lattice relaxation times of water were measured at increasing magnetic field strengths. Strong radiation damping was observed at each magnetic field strength when using inversion-recovery experiments. To measure the relaxation times in the presence of radiation damping, several experimental methods of saturation recovery to measure spin-lattice relaxation were applied to a 90% H(2)O sample to obtain results as a function of field strength for proton frequencies from 300 to 800 MHz. (C) 2010 Elsevier B.V. All rights reserved.