It is important to know the neutron yield, the spatial distribution, and the spectra emitted from a generator when performing any quantitative measurements. An extremely intense (d, t)-driven neutron generator is used in the LOTUS fusion blanket program. The planned measurements include integral tritium and 233U breeding as well as heat deposition rate studies in blankets representative of fusion reactor blankets. Quantitative estimates of these integral parameters demand precise determination of the characteristics of the neutron generator. Extensive foil activation measurements have been carried out to determine the reaction rate distribution and the neutron yield by a proposed method. A comparison between the calculated and measured reaction rates and the distribution confirm the adequacy of the cross-section sets and the geometry description of the complete experimental arrangement.