A sophisticated model is presented for the calculation of prompt-response self-powered neutron (SPN) detectors used for stationary as well as nonstationary neutron flux measurements in nuclear reactor cores. The technique recommended for calculating the unit sensitivity in terms of A/(cm) per unit flux takes the following into account:, neutron self-shielding factor of the emitter, flux depression correction, Compton and photoelectron production rate due to self-absorption of the gamma-ray cascade emitted immediately after neutron capture, electron escape probability from the emitterm, loss of electron energy within the emitter, range of the electrons in the insulator which contains a space-charge electric field., Calculated thermal and fast unit sensitivities in a typical light-water-reactor neutron spectrum for four potential prompt-response SPN detectors, whose emitters consist of cobalt, cadmium, erbium, and hafnium, are compared with experimental data and are found to be in satisfactory agreement.