[en] Measured and calculated neutron energy spectra from 14-MeV neutrons streaming through stainless steel ducts having length-to-diameter raios of 14.8 and 38.2 are compared in this paper. The measured data were obtained using an NE-213 liquid scintillator and the calculated data were obtained using the Monte Carlo code MCNP and the discrete ordinates code DOT 4.3. For both duct geometries, the spectra calculated using the MCNP code are in reasonable agreement with the measured data ranging from a few percent to a factor of two, depending on the detector location and duct. The spectra calculated using the DOT code are in fair agreement (30%) for cases where the detector is on the duct axis, but are in poor agreement, up to an order of magnitude, when the detector is off axis. 6 refs., 7 figs., 4 tabs