Numerical results for the time asymptotic neutron flux in a pulsed experiment, and for the thermal utilization factor in an infinite slab lattice, are derived using invariant imbedding. An isotropic separable kernel is assumed. It is shown that, though the neutron spectrum is strongly dependent on the shape of the kernel and thus cannot hope to be accurately predicted with a separable kernel, the qualitative behavior is in good agreement with previous computations. Moreover, some other features (the angular dependence of the flux, and the thermal utilization factor) are shown to have less dependence on the thermalization model, and are thus accurately predicted.