Fusion reactions at low energy

Conference · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5747063

Beckerman, M

Fusion measurement methods at low energies are briefly described, and experimental and theoretical fusion cross sections for /sup 58/Ni + /sup 58/Ni, /sup 58/Ni + /sup 64/Ni and /sup 64/Ni + /sup 64/Ni reactions are discussed. It is shown that quantal tunneling calculations do not describe the near- and sub-barrier behavior of the fusion data. Instead, the WKB predictions fall progressively further blow the experimental results as the energy is lowered. At far subbarrier energies the measured cross sections exceed the WKB predictions by more than three orders of magnitude. The unexpectedly strong dependence of the fusion probability upon the nuclear valence structure is illustrated and discussed. The relationship of channel coupling and quantal tunneling is discussed. In conclusion, it was established that atomic nuclei fuse far more readily at low energies that would be expected from quantal tunneling considerations alone. It was found that the behavior of the cross sections for fusion depends strongly upon the valence structure of the collision partners. This structural dependence extends from light 1p-shell systems to systems involving nearly 200 nucleons. These new phenomena may be viewed as characterizing the tunneling of a quantal system with many degrees of freedom. The failure of standard tunneling models may be understood as resulting from the ability of the dinuclear system to tunnel into the classically forbidden region by means of couplings to intrinsic degrees of freedom. 38 refs. (WHK)

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AS05-76ER04936; AC05-84OR21400
• OSTI ID: 5747063
• Report Number(s): CONF-850376-1; ON: DE85010561
• Resource Relation: Conference: Symposium on semiclassical descriptions of atomic and nuclear collisions, Copenhagen, Denmark, 25 Mar 1985; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
FUSION REACTIONS
NUCLEAR REACTION KINETICS
HEAVY ION REACTIONS
NICKEL 58 REACTIONS
NICKEL 58 TARGET
NICKEL 64 REACTIONS
NICKEL 64 TARGET
CROSS SECTIONS
ENERGY DEPENDENCE
TUNNEL EFFECT
WKB APPROXIMATION
CHARGED-PARTICLE REACTIONS
KINETICS
NUCLEAR REACTIONS
REACTION KINETICS
TARGETS
653003* - Nuclear Theory- Nuclear Reactions & Scattering
651515 - Nuclear Properties & Reactions
A=39-58
Theoretical- Nuclear Reactions & Scattering- (-1987)
651615 - Nuclear Properties & Reactions
A=59-89
Theoretical- Nuclear Reactions & Scattering- (-1987)
651525 - Nuclear Properties & Reactions
A=39-58
Experimental- Nuclear Reactions & Scattering- (-1987)
651625 - Nuclear Properties & Reactions
A=59-89
Experimental- Nuclear Reactions & Scattering- (-1987)