To investigate the impact of shell closure on N/Z of ^206-216Rn^* using neutron multiplicity as a probe

¹ Department of Physics, Banaras Hindu University, Varanasi - 221005, India
² Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi - 110067, India
³ Variable Energy Cyclotron Centre, Kolkata - 700064, India
⁴ Department of Physics, Panjab University, Chandigarh - 160014, India

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
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Published online: 13 May 2026

Abstract

The fission timescale of the compound nucleus (CN) ²⁰⁶Rn, formed through the reaction ²⁸Si+¹⁷⁸Hf, has been investigated using pre-scission neutron multiplicities as a diagnostic probe within the excitation energy range of 61–90 MeV. The obtained results for the ²⁰⁶Rn system have been compared with available experimental data for other radon isotopes (^{208,210,212,214,216}Rn) to examine the influence of shell closures on the total neutron multiplicity. A distinct trend has been identified in the neutron-to-proton (N/Z) ratio dependence, wherein the total neutron multiplicity decreases as the compound nucleus approaches shell closure and subsequently increases as it moves away from it. Furthermore, clear signatures of shell effects have been observed at excitation energies exceeding 50 MeV; an energy regime where such effects were not reported in earlier investigations.