Spin diffusion in doubly spin polarized atomic deuterium

Using an extension of the Boltzmann equation for the Wigner distribution appropriate for dilute spin 1 systems, spin diffusion equations are derived in the limit of large nuclear polarization in the non-degenerate régime. As an example of a system to which this work may be applied, the domain of validity of the Boltzmann equation for doubly spin-polarized deuterium, D↓↓, is studied. The effect of a finite field gradient is discussed. A calculated spin wave spectrum for a model one-dimensional system in the presence of a gradient is presented. Analogous effects in spin 1/2 systems are compared and contrasted.