## Abstract

Positrons and electrons from the internal pair conversion (IPC) decay of states populated in near-barrier collisions of very heavy ions have been studied using the APEX spectrometer. Using inelastic [Formula Presented] scattering at 5.90 MeV/nucleon, the gamma and IPC branches of the well-known [Formula Presented] decay of the first [Formula Presented] state were kinematically reconstructed and the IPC-to-gamma branching ratio was determined to be [Formula Presented]. We have also performed experiments with actinide beams or targets; [Formula Presented], [Formula Presented], [Formula Presented], and [Formula Presented], which resulted in the observation of new gamma-ray transitions from high-lying states in [Formula Presented] and [Formula Presented]. None of these were populated with sufficient strength such that IPC could produce statistically significantly peaks in positron-electron sum energy spectra.

Original language | English (US) |
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Pages (from-to) | R2755-R2759 |

Journal | Physical Review C - Nuclear Physics |

Volume | 55 |

Issue number | 6 |

DOIs | |

State | Published - 1997 |

## All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics