Integral experiments with a neutron source based on the T(d,n)α reaction require a good knowledge of the source neutron distribution. The source neutrons are energy-angle distributed with an energy spread of a few mega-electron-volts and anisotropy emission of a few percent.The characterization of the 14-MeV neutron source of the Frascati Neutron Generator (FNG) has been carried out using an absolutely calibrated U N a t microfission chamber with plane electrodes and 9 3 Nb(n,2n) 9 2 m Nb activation reaction. The reaction rates have been measured at different angles with respect to the beam direction. The experimental results are compared with the corresponding quantities calculated by using a Monte Carlo code (MCNP) with an ad hoc source model. The calculated neutron emission reproduces the measured one satisfactorily well. Improvement of the source model used is discussed.