In this article a nonlinear one-dimensional stationary transport equat
ion with general boundary conditions is considered where an abstract b
oundary operator relates the incoming and the outgoing fluxes. Existen
ce results are proved in the case where the collision operator is of t
he Hammerstein type. In particular, it is shown that these results rem
ain valid for multidimensional geometry with vacuum boundary condition
s. Sufficient conditions are given in terms of collision frequency and
scattering kernel assuring the existence and uniqueness of solutions.
The article ends with the discussion of the case of multiplying bound
ary conditions. (C) 1996 American Institute of Physics.