Sequential fissions of heavy nuclear systems

TL;DR

This paper investigates the sequential fission processes in heavy nuclear systems during Xe+Sn collisions, revealing how the time scale between break-ups decreases with energy and transitions to quasi-simultaneous multifragmentation.

Contribution

It demonstrates that three-fragment channels result from two successive binary splittings and analyzes Coulomb effects and timing, providing new insights into nuclear fragmentation dynamics.

Findings

Three-fragment channels arise from sequential binary splittings.

Time scale between break-ups decreases with increasing energy.

Transition to quasi-simultaneous multifragmentation above 18 MeV/A.

Abstract

In Xe+Sn central collisions from 12 to 20 MeV/A measured with the INDRA 4$\pi$ multidetector, the three-fragment exit channel occurs with a significant cross section. In this contribution, we show that these fragments arise from two successive binary splittings of a heavy composite system. Strong Coulomb proximity effects are observed in the three-fragment final state. By comparison with Coulomb trajectory calculations, we show that the time scale between the consecutive break-ups decreases with increasing bombarding energy, becoming compatible with quasi-simultaneous multifragmentation above 18 MeV/A.