New isotope Mc286 produced in the Am243+Ca48 reaction

Abstract

In this paper, we present results of the second experiment on the synthesis of Mc isotopes in the Am243+Ca48 reaction performed at the gas-filled separator DGFRS-2 of the SHE Factory at JINR. The new isotope Mc286 was synthesized, and its half-life of 20+98−9 ms and α-particle energy of 10.71±0.02 MeV were determined. A Mc286 α−decay chain was recorded down to the spontaneous fission of Db266. The spontaneous fission of Rg279 was observed for the first time in one of four new decay chains of Mc287. The excitation function of the reaction was measured at three Ca48 energies of 242, 250, and 259 MeV; the latter resulted in the first observation of the 5n−evaporation channel with a cross section of 0.5−0.4+1.3 pb. The decay properties of 21 previously known odd−Z isotopes were improved. The potential for an electron-capture decay mode is discussed for Mc288 and Nh284 isotopes. The half-lives of spontaneously fissioning nuclei produced in the Ca48−induced reactions with actinide targets are compared with several theoretical predictions.Received 10 October 2022Accepted 22 November 2022DOI:https://doi.org/10.1103/PhysRevC.106.064306©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAlpha decayBeta decayFissionLow & intermediate energy heavy-ion reactionsNuclear fusionNuclear reactionsNuclear structure & decaysRare & new isotopesPropertiesA ≥ 220TechniquesSpectrometers & spectroscopic techniquesNuclear Physics