Prompt-fission-neutron spectra of /sup 233/U, /sup 235/U, /sup 239/Pu and /sup 240/Pu relative to that of /sup 252/Cf. [550 and 850 keV]

Abstract

The prompt-neutron-induced-fIssion spectre of 233 U, 23! >U, 239 Pu and 2"tOp u are measured relative to the prompt-spontaneousfission-neutron spectrum of 252 Cf. The fission of 233 U, 235 U, and 23^P U is induced by ~550 keV neutrons and that of 21 *°Pu bỹ 850 keV neutrons. The emitted fission neutrons are observed over the energy range i 0.5-10.0 MeV using tirae-of-flight techniques. Analysis of the measured values indicates that the average-fission-neutron energies are-123±30(233 U),-157±24(235 U),-76±29(239 Pu) and-46±29(21 +0p u) keV relative to that of 2 "cf. The experimental results are compared with those of ENDF/B-V and a simple behavior of average-prompt-fission-neutron energies is suggested.

Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

“…Its neutron emission is about 3.757 neutrons per fission [74] and 1 mg of 252 Cf generates ∼2.3×10 9 neutrons/s [75]. Californium neutron energy spectrum is similar to a fission reactor, with an average energy of 2.13 MeV [76,77]. Consequently, compact 252 Cf neutron sources can provide an ideal nonreactor source of neutrons for lower-flux applications.…”

Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from Major Evaluated Data Libraries

“…Its neutron emission is about 3.757 neutrons per fission [73] and 1 mg of 252 Cf generates ∼2.3×10 9 neutrons/s [74]. Californium neutron energy spectrum is similar to a fission reactor, with an average energy of 2.13 MeV [75,76]. Consequently, compact 252 Cf neutron sources can provide an ideal nonreactor source of neutrons for lower-flux applications.…”