## Prompt Neutron Emission Multiplicity Distributions and Average Values, <ν>, at 2200 Meter per Second for the Fissile NuclidesBrookhaven National LaboratoryUpton, New York 11973, USA The prompt neutron emission multiplicity distribution, P _{ν}, is of interest for methods of self-calibration and for auto-correlation to assay fissionable material for nuclear safeguards. <ν>, the average value of P_{ν}, is of interest at neutron thermal energies since it is related to the neutron multiplication factor and it is used as a normalizing point for energy dependent values of <ν>. Values of P_{ν} and <ν> have been determined at the standard neutron energy of 0.0253 ev for the neutron induced fission of the four fissile nuclides, ^{233,235}U, and ^{239,241}Pu. Revised <ν> values have been obtained by re-evaluating <ν> experiments measured at 2200 meter/second relative to the <ν> from the spontaneous fission of ^{252}Cf. These revised values of <ν> have been used to renormalize the measured P_{ν} values. The revised values of <ν> are all about 1/4% to 1/2% smaller than the corresponding values of ENDF/B-V.KEYWORDS: <ν>, P_{ν}, E_{n} = 0.025 ev, ^{233}U, ^{235}U, ^{239}Pu, ^{241}Pu |