Analysis of Dipole Relaxation Time for Water Molecules at Temperature of 293 K

Abstract

The study of dipole relaxation time for water molecules at 293 K is an important aspect from physics / communication / electronic engineering point of view since it gives rise to the dielectric absorption losses for r.f. fields up to about  of frequencies. Here molecular (dipole) relaxation time is analyzed and calculated for the water molecules at temperature of293 K . This assumes that the water medium is an intermediate one to a solid state and a gaseous state. The molecule of the water undergoes coupled mass vibrations on one hand and simultaneously it has an average thermal velocity on other hand as given by the kinetic theory of gasses. In other words, this is a quasi-stationary: quasi moving system of the molecules, where molecule-molecule collisions take place which are described by gas kinetics. The expression which is obtained for the molecular collision frequency, determines the dipole relaxation time coming in the picture of relaxation spectrum in r.f. region for the water molecules. The present theory given here determines fairly well the value of dipole relaxation time for water at temperature of293 K  viz., the relaxation time is experimentally located near the free space wavelength of  in the relaxation spectrum of water. Purpose of this work is to show in a simple manner, how dipole relaxation time for water molecules at 293 K comes in the analysis of scattering of the dipoles at collisions with each other.