An approximate evaluation of the branch‐cut integral which occurs in the rigorous solution of the Boltzmann equation for intermediate and large distances is of importance in shielding problems. Such an evaluation leads to Eq. (20) for the point source and Eq. (24) for the plane source. Equation (20) is actually 23 percent high for zero absorption (f=0) andr&sgr;=7, but the error decreases with increasingr&sgr; andf. It is seen that the branch‐cut term is not simply the contribution of noncollided neutrons.Figure 2 is a plot of the region in thef−r&sgr; plane where the two terms are comparable.