Fission Dynamics Investigation with VAMOS and Second Arm

by Indu Jangid (3^rd year PhD student)

The fission process is strongly determined by both the nuclear structure and the nuclear dynamics, which drive the system from its initial state to final break-up through various stages of extreme deformation. The resultant fission fragments, along with the neutron evaporation, emerge as promising parameters for elucidating the underlying mechanisms governing the fission process.

The VAMOS++ spectrometer is a large solid-angle, ray-tracing magnetic spectrometer that benefits from inverse kinematics to provide complete isotopic identification of the fission fragments. Conversely, the FALSTAFF spectrometer, employing low-pressure gaseous detectors, is designed to provide constraining data from neutron-induced fission. An experiment was conducted at GANIL with VAMOS++ spectrometer in conjunction with the Second arm (Modified version of FALSTAFF for inverse kinematics) – to simultaneously measure both fission fragments in coincidence.

In this experiment, a 238U beam at coulomb energies was impinged on the beryllium (9Be) target to produce different fissioning systems via fusion and transfer reactions. In this work, the full isotopic identification of the fission fragments from 247Cm was accomplished, with the identification of fissioning systems based on coincident nuclear charge measurements from the two arms. The elemental yields and mass yields for three different systems will be presented and compared with the present-day fission models, and will be discussed in terms of fission modes and nuclear structure.