Mass distributions in monoenergetic-neutron-induced fission of /sup 232/Th

Journal Article · Tue Jul 01 04:00:00 EDT 1980 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.22.152· OSTI ID:5361630

Glendenin, L E; Gindler, J E; Ahmad, I; Henderson, D J; Meadows, J W

Fission product yields for 38 masses were determined for the fission of /sup 232/Th with essentially monoenergetic neutrons of 2.0, 3.0, 4.0, 5.9, 6.4, 6.9, 7.6, and 8.0 MeV. Fission product activities were measured by Ge(Li) ..gamma..-ray spectrometry of irradiated /sup 232/Th foils and by chemical separation of the fission product elements followed by ..beta.. counting. The mass yield data for /sup 232/Th(n,f ) show a sensitive increase of fission yields in the near-symmetric mass region (valley) with increasing incident neutron energy E/sub n/ and a pronounced dip in yield at the onset of second-chance fission just above the neutron binding energy (at approx. 6 MeV) where the excitation energy is lowered by competition with neutron evaporation prior to fission. The effect of second-chance fission is also seen in the yields of asymmetric peak products. A distinct third peak is observed at symmetry in the valley of the mass distribution, and enhanced yields are observed in the asymmetric peaks at masses associated with even Z (proton pairing effect). The fission yeilds of /sup 232/Th(n,f ) are compared with those of /sup 238/U(n,f ) and /sup 232/Th(..gamma..,f ).

• Research Organization: Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5361630
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 22:1; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

652026* -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Spontaneous & Induced Fission-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
BINDING ENERGY
ENERGY
ENERGY RANGE
EVAPORATION MODEL
FISSION
FISSION FRAGMENTS
GAMMA SPECTROMETERS
HADRON REACTIONS
MASS SPECTRA
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 01-10
NEUTRON REACTIONS
NUCLEAR FRAGMENTS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEON REACTIONS
SPECTRA
SPECTROMETERS
TARGETS
THORIUM 232 TARGET
URANIUM 238 TARGET