SYMMETRY OF NEUTRON-INDUCED U$sup 235$ FISSION AT INDIVIDUAL RESONANCES

Journal Article · Mon May 15 04:00:00 EDT 1961 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.122.1286· OSTI ID:4009890

Cowan, G A; Turkevich, A; Browne, C I

Neutrons in the resonance energy region from a nuclear explosion are resolved by time-of-flight and are used to induce fissions in U/sup 2//sup 3//sup 5/ attached to a revolving wheel. The symmetry of fission at individual resonances from approximately 10 to 60 ev is examined by radiochemical means. As measured by the yield ratio of Ag/sup 1//sup 1//sup 1//Mo/sup 9//sup 9/, the probability of symmetric fission decreases at some resonances by a maximum of 10% compared to thermal fission of U/sup 2//sup 3//sup 5/ and at other resonances increases by a maximum of 40%. With varying degrees of assurance, nine resonances are identified with an increase in symmetry; five more regions of increased symmetry are associated with resonances or a background effect. Twenty resonances are identified with a decrease in symmetry. In a sample containing 500 levels in the resonance region, there is no level with a Ag/sup 1//sup 1//sup 1/ yield even one-thirtieth as great as the Mo/sup 9//sup 9/ yield. It is thus improbable that there are any neutron resonances in U/sup 2//sup 3//sup 5/ that lead to predominantly symmetric fission. (auth)

• Research Organization: Los Alamos Scientific Lab., N. Mex.
• NSA Number: NSA-15-018803
• OSTI ID: 4009890
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 122; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BACKGROUND
ENERGY LEVELS
ENERGY RANGE
FISSION
MEASURED VALUES
MOLYBDENUM 99
NEUTRON SPECTROMETERS
NUCLEAR EXPLOSIONS
PHYSICS
RADIOCHEMISTRY
RESONANCE
RESONANCE NEUTRONS
SILVER 111
THERMAL NEUTRONS
URANIUM 235
VELOCITY