Spin dynamics of the superfluid B phase and spatially inhomogeneous coherently precessing structures

The equations of the inhomogeneous spin dynamics of the superfluid B phase of 3He are derived. In the hydrodynamic region, a generalization of the Leggett-Takagi two-fluid hydrodynamics to the spatially inhomogeneous case is obtained. Near the critical temperature, approximate equations for the macroscopic description of the collisionless spin dynamics of 3He-B are found. A solution of these equations is obtained that represents a coherently precessing inhomogeneous distribution of the magnetization; as T→Tc, this solution goes over into the recently discovered two-component structure in normal 3He. It is shown that, in contrast to normal helium, the two-component coherently precessing distribution in 3He-B exists both in a weakly inhomogeneous and completely homogeneous external field. An investigation is made of the relaxation of the structure and the temperature region in which it exists