Systematic analysis of mass yield curves in low-energy fission of actinides

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Physical Review (Section) C: Nuclear Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevC.40.2144· OSTI ID:5091476

Ohtsuki, T; Hamajima, Y; Sueki, K; Nakahara, H ^[1]; Nagame, Y; Shinohara, N; Ikezoe, H ^[2]

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1. Tokyo Metropolitan University, Department of Chemistry, Faculty of Science, Fukasawa, Setagaya, Tokyo 158, Japan (JP)
2. Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-11, Japan (JP)

Mass yield curves in low-energy proton-induced fissions of {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 242}Pu, {sup 244}Pu, {sup 241}Am, and {sup 243}Am were measured. The full widths at half maximum (FWHM) of the heavier asymmetric peak of the mass yield curves showed a sudden dip in the region of {ital A}{sub {ital f}}=240--245. The correlation between the {ital P}/{ital V} ratio and the FWHM of the asymmetric mass yield peak was obtained as a function of proton energy. The FWHM values were independent of the incident proton energy as long as the {ital P}/{ital V} ratio was larger than 10 for all the fissioning systems studied. The excitation energy dependence of the mass yield curves was investigated. It was found that the excitation energy dependence of symmetrically divided fission products was apparently different from that of asymmetrically divided ones. With a simple assumption of the two-mode hypothesis, the observed mass yield curves could be decomposed into two mass yield curves. Asymmetric mass yield peaks could be best represented by the sum of two Gaussians, and their variation could be expressed by the variation of Gaussian parameters. The peak positions of the two Gaussians were always {ital A}=133--135 and {ital A}=140--142 for all the investigated fissioning nuclides. The preference of those fragment masses is discussed in terms of both the scission-point model and the saddle-point model.

• OSTI ID: 5091476
• Journal Information: Physical Review (Section) C: Nuclear Physics; (USA), Vol. 40:5; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMERICIUM 241
PROTON REACTIONS
AMERICIUM 243
NEPTUNIUM 237 TARGET
PLUTONIUM 242
PLUTONIUM 244
FISSION
URANIUM 233 TARGET
URANIUM 235 TARGET
URANIUM 238 TARGET
ASYMMETRY
ENERGY DEPENDENCE
EXPERIMENTAL DATA
FISSION FRAGMENTS
FISSION YIELD
MASS SPECTRA
SHELL MODELS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
AMERICIUM ISOTOPES
BARYON REACTIONS
CHARGED-PARTICLE REACTIONS
DATA
EVEN-EVEN NUCLEI
HADRON REACTIONS
HEAVY NUCLEI
INFORMATION
ISOTOPES
MATHEMATICAL MODELS
NUCLEAR FRAGMENTS
NUCLEAR MODELS
NUCLEAR REACTION YIELD
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUMERICAL DATA
ODD-EVEN NUCLEI
PLUTONIUM ISOTOPES
RADIOISOTOPES
SPECTRA
TARGETS
YEARS LIVING RADIOISOTOPES
YIELDS
652020* - Nuclear Properties & Reactions
A=220 & above
Experimental