28th International Scientific Conference of Young Scientists and Specialists (AYSS-2024)

Study of fission and quasifission reaction mechanisms through mass-energy distribution measurements

31 Oct 2024, 14:50

15m

4-451 (MLIT)

Oral Experimental Nuclear Physics Experimental Nuclear Physics

Speaker

Dr ANIRUDDHA DEY (Flerov Laboratory of Nuclear Reaction, Joint Institute for Nuclear Research)

Description

The collision of two heavy nuclei takes a special place in nuclear reactions studies due to the collective rearrangement of a large number of nucleons in a very short span of time, typically of the order 10${}^{-20}$ seconds. During this collision, a significant number of nucleons are transferred between the projectile and target nuclei due to the influence of different reaction mechanisms [1]. In reactions with heavy ions at energies close to the Coulomb barrier $–$ complete fusion, quasifission (QF), and deep-inelastic collision are competing processes. Therefore, a comprehensive understanding of the reaction dynamics of these processes is one of the key ingredients for the synthesis of Super Heavy Elements (SHE) [2, 3].

The experiments were performed at the Flerov Laboratory of Nuclear Reactions (FLNR), JINR, Russia, using energetic beams of ${}^{16}$O and ${}^{48}$Ca delivered from the $U400$ cyclotron. The thin targets of ${}^{208}$Pb and ${}^{176}$Yb were bombarded with the ${}^{16}$O and ${}^{48}$Ca beams, respectively at different energies above the Coulomb barrier to produce the same fissioning nucleus, ${}^{224}$Th. The measurements of the reaction binary products were carried out by utilizing the double-arm time-of-flight (TOF) spectrometer $CORSET$ [4]. Assuming the conservation of mass of the composite system of projectile and target, the double-velocity method was employed to determine the mass and energy of the reaction products. The Mass-Total Kinetic Energy (M-TKE) distributions of the primary binary fragments from ${}^{224}$Th have been measured. Different aspects of the fission and quasifission reaction dynamics have been studied through detailed multimodal analysis [3] on the experimental mass and energy distributions of the fission fragments.

References:
1. R. Vandenbosch, J.R. Huizenga, Nuclear Fission, Academic, New York (1973).
2. G. N. Knyazheva $\mathit{\text{et al.}}$, Phys. Rev. C $\mathbf{75}$, 064602 (2007).
3. E. M. Kozulin $\mathit{\text{et al.}}$, Phys. Rev. C $\mathbf{105}$, 024617 (2022) and references therein.
4. E. M. Kozulin $\mathit{\text{et al.}}$, Instrum. Exp. Tech. $\mathbf{51}$, 44 (2008).