Measurement of the energy dependence of prompt fission neutron emission from /sup 233/U, /sup 235/U, and /sup 239/Pu for E = 0. 0005 to 10 MeV relative to emission from spontaneous fission of /sup 252/Cf

A series of experiments has been performed to measure the dependence on the incident neutron energy of anti nu/sub p/(E), the average number of prompt neutrons emitted per fission, of /sup 233/U, /sup 235/U, and /sup 239/Pu relative to anti nu/sub p/ (/sup 252/Cf), the average number of prompt neutrons emitted in spontaneous fission of /sup 252/Cf. The incident energy range was 0.0005 to 10 MeV. A white neutron source was generated by the Oak Ridge Electron Linear Accelerator and the energies of the neutrons incident on the fissile samples were determined by time-of-flight techniques. The fissile sample and the /sup 252/Cf standard were contained in a fission chamber surrounded by a large volume (0.91 m/sup 3/) liquid scintillator loaded with gadolinium. Fissions were detected by the fission chamber and the neutrons were detected by the scintillator. The results for /sup 239/Pu agree over most of the energy range with the results of the evaluation of Manero and Konshin. However, the present results are larger for /sup 235/U than those of Manero and Konshin and for /sup 233/U the present data yield a different energy dependence in the interval 100 to 600 keV. Final results are displayed.