Scientists from the Laboratory of Nuclear Reactions and Laboratory of Theoretical Physics at JINR restored and presented an unusually symmetrical shape of the prompt neutron multiplicity distribution in ²⁵⁰Nо for the first time. Research was conducted in cooperation with colleagues from scientific centres in France, Kazakhstan, and Russia.

As part of the research, specialists used the complete-fusion reaction ²⁰⁴Pb(⁴⁸Ca, 2n)²⁵⁰Nо to study two activities of ²⁵⁰Nо with distinct half-lives. A total of 1357 events were observed in the SFiNx Neutron Detection System. The average number of neutrons emitted per spontaneous fission of ²⁵⁰Nо was determined to be (4.1 ± 0.1). Additionally, physicists performed statistical tests to compare the prompt neutron multiplicity distributions associated with the ground state and K-isomer state decays.

Restored prompt neutron multiplicity distribution of ²⁵⁰Nо obtained in the experiment (circles with uncertainty bars) and theoretical predictions (squares)

An article on the study of prompt neutron emission in ²⁵⁰Nо spontaneous fission was published in Chinese Physics C. The Joint Institute for Nuclear Research is represented by the following scientists: R.S. Mukhin, A.V. Isaev, A.V. Andreev, M.L. Chelnokov, V.I. Chepigin, H.M. Devaraja, I.N. Izosimov, A.A. Kuznetsova, O.N. Malyshev, A.G. Popeko, Yu.A. Popov, A. Rahmatinejad, B. Sailaubekov, T.M. Shneidman, E.A. Sokol, A.I. Svirikhin, M.S. Tezekbayeva, M.A. Bychkov and A.V. Yeremin. In addition, the research team included specialists from Dubna State University, Institute of Nuclear Physics of the Ministry of Energy of the Republic of Kazakhstan, Gumilyov Eurasian National University, Kazan Federal University, University of Strasbourg, and Paris-Saclay University.