Fission of /sup 255,256/Es, /sup 255en-dash257/Fm, and /sup 258/Md at moderate excitation energies

Journal Article · Wed Aug 01 04:00:00 EDT 1984 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.30.559· OSTI ID:6792904

Britt, H C; Hoffman, D C; van der Plicht, J; Wilhelmy, J B; Cheifetz, E; Dupzyk, R J; Lougheed, R W

The fission of /sup 255,256/Es, /sup 255en-dash257/Fm, and /sup 258/Md has been studied in the excitation energy range from threshold to 25 MeV. A target of /sup 254/Es was used in the direct reaction studies; (d,pf), (t,pf), (/sup 3/He,df), (/sup 3/He,pf), and in the compound induced fission reactions formed with p, d, t, and ..cap alpha.. particle projectiles. Coincident fission fragment energies were recorded along with (in the direct reaction studies) the outgoing light charged particle. The mass and kinetic energy distributions were studied as a function of nuclear excitation energy. The observed bulk properties were consistent with established systematics in that they exhibited an asymmetric mass distribution and a phenomenologically consistent total kinetic energy. However, the systems demonstrated a fission decay mode which we ascribe to high energy symmetric fission decay. This component, though somewhat arbitrary in its definition, showed a general decrease in yield as a function of increasing nuclear excitation energy. This observed rapid change in fission properties between ''normal'' and high energy symmetric fission probably points to the important observable consequences that can occur from small variations in the potential energy surface.

• Research Organization: Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6792904
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 30:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

652025 -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Nuclear Reactions & Scattering-- (-1987)
652026* -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Spontaneous & Induced Fission-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
DAYS LIVING RADIOISOTOPES
DETECTION
DEUTERON REACTIONS
DIRECT REACTIONS
EINSTEINIUM 254 TARGET
EINSTEINIUM 255
EINSTEINIUM 256
EINSTEINIUM ISOTOPES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FERMIUM 255
FERMIUM 256
FERMIUM 257
FERMIUM ISOTOPES
FISSION
FISSION FRAGMENT DETECTION
HEAVY NUCLEI
HELIUM 3 REACTIONS
HOURS LIVING RADIOISOTOPES
ISOTOPES
MASS SPECTRA
MENDELEVIUM 258
MENDELEVIUM ISOTOPES
MINUTES LIVING RADIOISOTOPES
NUCLEAR REACTIONS
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIATION DETECTION
RADIOISOTOPES
SPECTRA
TARGETS
TRITON REACTIONS