Atomic clusters, decay modes

There are four modes of radioactive decay that are common and that are exhibited by the decay of naturally occurring radionucHdes. These four are a-decay, j3 -decay, electron capture and j3 -decay, and isomeric or y-decay. In the first three of these, the atom is changed from one chemical element to another in the fourth, the atom is unchanged. In addition, there are three modes of decay that occur almost exclusively in synthetic radionucHdes. These are spontaneous fission, delayed-proton emission, and delayed-neutron emission. Lasdy, there are two exotic, and very long-Hved, decay modes. These are cluster emission and double P-decay. In all of these processes, the energy, spin and parity, nucleon number, and lepton number are conserved. Methods of measuring the associated radiations are discussed in Reference 2 specific methods for y-rays are discussed in Reference 1. 

Other Decay Modes in Atomic and Molecular Clusters... 

To examine the effects of anharmonicity on the decay of excited clusters, calculations were performed for hot clusters in which the alternate, truncated harmonic potential, equations (7) and (8), was employed as the atomic pair potential. While the interatomic pair potential was harmonic in form, the entire cluster was not a harmonic system since displacements along the normal mode coordinate were not subject to restoring forces which were linear functions solely of the displacements along those coordinates. The change in potential nonetheless causes a change in the density of states for the cluster. 

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