12. 3-min /sup 256/Cf and 43-min /sup 258/Md and systematics of the spontaneous fission propertiesof heavy nuclides
The new isotope 12.3-min /sup 256/Cf was produced via the /sup 254/Cf(t,p) reaction, and a new 43-min isomer of /sup 258/Md was produced via the /sup 255/Es(..cap alpha..,n) reaction. The fragment mass and kinetic energy distributions from the spontaneous fission of /sup 256/Cf were found to be very similar to those from the spontaneous fission of lighter Cf isotopes. The mass division is primarily asymmetric, and the average total kinetic energy is 189.8 +- 0.9 MeV. The 43-min /sup 258/Md presumably decays by electron capture and provides an opportunity to study the mass and kinetic energy distributions from the spontaneous fission of the 380-..mu..s /sup 258/Fm daughter. The observed narrow, symmetric mass distribution and the most probable total kinetic energy of 238 +- 3 MeV are similar to those reported for the spontaneous fission of /sup 259/Fm but show a sharp increase in symmetric mass division and total kinetic energy compared to /sup 257/Fm and the lighter Fm isotopes. No such abrupt change in properties was observed for /sup 256/Cf, which, like /sup 258/Fm, has 158 neutrons. The marked difference between the spontaneous fission properties of the heavier Fm isotopes and those of other spontaneously fissioning nuclides is compared to some theoretical predictions.
- Research Organization:
- Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87545
- OSTI ID:
- 5482680
- Journal Information:
- Phys. Rev., C; (United States), Vol. 21:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALPHA REACTIONS
THREE-NUCLEON TRANSFER REACTIONS
CALIFORNIUM 254 TARGET
TRITON REACTIONS
CALIFORNIUM 256
SPONTANEOUS FISSION
EINSTEINIUM 255 TARGET
FERMIUM 259
MENDELEVIUM 258
ELECTRON CAPTURE DECAY
TWO-NUCLEON TRANSFER REACTIONS
COINCIDENCE SPECTROMETRY
FISSION FRAGMENT DETECTION
HALF-LIFE
KINETIC ENERGY
MASS SPECTRA
NEUTRON SPECTRA
PROTON SPECTRA
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
BETA DECAY
CALIFORNIUM ISOTOPES
CHARGED-PARTICLE REACTIONS
DECAY
DETECTION
DIRECT REACTIONS
ENERGY
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FERMIUM ISOTOPES
FISSION
HEAVY NUCLEI
ISOTOPES
MENDELEVIUM ISOTOPES
MINUTES LIVING RADIOISOTOPES
MULTI-NUCLEON TRANSFER REACTIONS
NUCLEAR REACTIONS
NUCLEI
ODD-ODD NUCLEI
RADIATION DETECTION
RADIOISOTOPES
SPECTRA
TARGETS
TRANSFER REACTIONS
652012* - Nuclear Properties & Reactions
A=220 & above
Theoretical- Radioactive Decay- (-1987)
652015 - Nuclear Properties & Reactions
A=220 & above
Theoretical- Nuclear Reactions & Scattering- (-1987)
652016 - Nuclear Properties & Reactions
A=220 & above
Theoretical- Spontaneous & Induced Fission- (-1987)