The third form of Boltzmann equation involves only the angular flux st
the boundary while the usual transport equation deals with the angula
r flux at any point. The kernel of this equation is the infinite mediu
m Green's function and satisfies the lineer transport equation. The me
thod of solution of this equation is known as the CN method and is bas
ed on the Placzek lemma and depends ail the calculation of the infinit
e medium Green's function. Here, the well-known form of the Green's fu
nction in terms of elementary solutions is used to solve the third for
m of the transport equation and applications for the half-space albedo
problems for both isotropic and extremely anisotropic scatterings are
given. Uncollided neutrons are also taken into account.