Fig. 1. Photo of D-T neutron generator (a), inner structural diagram of D-T neutron generator (b), and schematic diagram of experimental system (c)

Fig. 2. The delayed gamma ray spectrum of copper activation foil

Fig. 3. Simulated neutron spectrum in copper activation foil

Fig. 4. Neutron spectrum measured at the sample position

Fig. 5. Neutron induced prompt gamma-ray spectra (a) and the fitting characteristic peaks (b) (color online)

Fig. 6. The ³He detector counts during measurement

Fig. 7. Dependence of net peak count rate with sample mass

Fig. 8. Delayed gamma-ray spectrum of U ore and the prompt γ-ray spectra of U ore and #4 sample (color online)