Bimodal fission

Conference · Wed Apr 19 04:00:00 EDT 1989

OSTI ID:6166771

Hulet, E. K.

In recent years, we have measured the mass and kinetic-energy distributions from the spontaneous fission of /sup 258/Fm, /sup 259/Md, /sup 260/Md, /sup 258/No, /sup 262/No, and /sup 260/(104). All are observed to fission with a symmetrical division of mass, whereas the total-kinetic-energy (TKE) distributions strongly deviated from the Gaussian shape characteristically found in the fission of all other actinides. When the TKE distributions are resolved into two Gaussians the constituent peaks lie near 200 and near 233 MeV. We conclude two modes or bimodal fission is occurring in five of the six nuclides studied. Both modes are possible in the same nuclides, but one generally predominates. We also conclude the low-energy but mass-symmetrical mode is likely to extend to far heavier nuclei; while the high-energy mode will be restricted to a smaller region, a region of nuclei defined by the proximity of the fragments to the strong neutron and proton shells in /sup 132/Sn. 16 refs., 7 figs., 1 tab.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6166771
• Report Number(s): UCRL-99678; CONF-890406-9; ON: DE89010782
• Country of Publication: United States
• Language: English

Related Subjects

652020* -- Nuclear Properties & Reactions
A=220 & above
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
DECAY
EVEN-EVEN NUCLEI
FERMIUM 258
FERMIUM ISOTOPES
FISSION
FISSION FRAGMENTS
HEAVY NUCLEI
ISOTOPES
MASS SPECTRA
MENDELEVIUM 259
MENDELEVIUM 260
MENDELEVIUM ISOTOPES
MICROSEC LIVING RADIOISOTOPES
NOBELIUM ISOTOPES
NUCLEAR DECAY
NUCLEAR FRAGMENTS
NUCLEAR REACTIONS
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIOISOTOPES
SPECTRA
SPONTANEOUS FISSION