Boundary conditions in the theory of the relaxation field

The perturbationf_ji^' generated by an external field in the distribution function is derived by integration of the Onsager-Fuoss equation of continuity. The solution isf_ji^'(r)=C(I+Ah₁+Bh₂) whereCI is a particular integral andh₁ andh₂ are solutions of the homogeneous equation. The physical significance of the boundary conditions which evaluate the constantsA andB is discussed. It is then shown that the conditionf_ji^'() 0 requiresB=0 and that the condition lim(f_ji^'/n²) 0 at zero concentration is satisfied if and only ifA=–1.