An Overview of Heavy-ion Collisions

Abstract

Abstract

A large number of experiments have been performed to explore the heavy-ion collisions dynamics using accelerator facilities available in India. The experimental results have revealed that in reactions induced by nucleons or light particles at energies of the order of a few tens MeV, the great majority of the processes one observes are of statistical nature though they cannot be interpreted as a consequence of the decay of a fully equilibrated compound nucleus. One observes, in reality that energy of ejectiles emissions are significantly greater than anticipated during compound nucleus evaporation, mostly generated at forward angles rather than possessing isotropic or symmetric angular distributions around 90°. These phenomenological models, some of semi-classical type, others with a smaller range of applicability, quantum statistics clarified these procedures, often very satisfactorily, even from a quantitative view point. Overall, these models are based on the hypothesis that the projectile-target interaction excites an initial simple passage and that a cascade of two-body nucleon-nucleon interactions (Projectile-target model not yet attained statistical equilibrium) leads to a subsequent sharing of excitation energy, the total angular momentum and any other constants of motion among all the nucleons of a composite system. This has provided a better insight of some new phenomenology, as heavier and faster projectiles become available and more exhaustive detection techniques are developed, an extremely rich typology of reactions between deep inelastic collisions and complete fusion emerges: prompt fission, pre equilibrium particle emission, incomplete fusion, one-step multifragmentation, fusion window etc. have been growing interests in recent years. Here the experiments performed in various facilitation centres in India including IUAC, VECC and BARC with a wide range of projectile–target combinations of a few tens MeV/nucleon have been presented and the results were used to explore the heavy-ion collisions mechanisms.

Keywords: Heavy-ions, deep inelastic collisions, compound nucleus, composite system, fusion window.

Cite this Article

Ayan Kumar Makar. An Overview of Heavy-ion Collisions. Journal of Nuclear Engineering & Technology. 2019; 9(2): 8–23p.