Fission of excited nuclei with Z{sup 2}/A = 20 - 33: Mass-energy distributions of fragments, angular momentum, and liquid-drop model
- Joint Institute for Nuclear Research, Moscow (Russian Federation); and others
The mass-energy distributions of fission fragments in the reactions {sup 20}Ne + {sup 99}Ru, {sup 106,110}Cd, {sup 112,118,134}Sn are measured by means of a two-arm time-of-flight spectrometer DEMAS. The fission of {sup 124}Ba in two ion-target combinations {sup 12}C + {sup 112}Sn and {sup 25}Mg + {sup 99}Ru is also studied. Global analysis of data obtained in (C) this study and data reported by other authors made it possible to determine the variances {sigma}{sub M}{sup 2} and {sigma}{sub E}{sup 2} of mass E and energy distributions as functions of the angular momentum l of the compound nucleus and nucleon composition. It is found that, for nuclei with Z{sup 2}/A {le}30 (in contrast to heavier nuclei), an increase in the angular momentum introduced into a nucleus undergoing fission leads to the narrowing of the mass distributions of fragments. The stability of nuclei to mass-asymmetric deformation is studied, and it is shown that the Sierk liquid-drop model with finite-range nuclear forces provides the closest description of experimental data in the region on Z{sup 2}/A {approximately} 20 - 30. The Businaro-Gallone point at which the nucleus is absolutely unstable to mass-asymmetric deformations is found to be (Z{sup 2}/A){sub BG} = 22.0 {+-} 0.6. 97 refs., 16 figs., 5 tabs.
- OSTI ID:
- 283085
- Journal Information:
- Physics of Atomic Nuclei, Vol. 58, Issue 12; Other Information: PBD: Dec 1995; TN: Translated from Yadernaya Fizika; 58: No. 12, 2140-2165(1995)
- Country of Publication:
- United States
- Language:
- English
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