Observation of the Superheavy Nuclide ²⁷¹ Ds

Abstract

With the recent commissioning of a gas-filled recoil separator at Institute of Modern Physics (IMP) in Lanzhou, the decay properties of 271Ds (Z = 110) were studied via the 208Pb(64Ni, n) reaction at a beam energy of 313.3 MeV. Based on the separator coupled with a position sensitive silicon strip detector, we carried out the energy-position-time correlation measurements for the implanted nucleus and its subsequent decay α's. One α-decay chain for 271Ds was established. The α energy and decay time of the 271Ds nucleus were measured to be 10.644 MeV and 96.8 ms, which are consistent with the values reported in the literature.

Search for Superheavy Nuclei

“…Because the measured α-particle energies are almost identical, the likely explanation is that the isomeric state has a longer half-life and decays by γ -rays or conversion electrons to the ground state. Furthermore, the appearance of 271 Ds in the same reaction was confirmed for three beam energies at BGS (44) and for one beam energy at IMP in Lanzhou (45). The 267 Ds observed by LBNL in cold fusion reactions and the 273 Ds observed by FLNR in hot fusion reactions require further experimental clarification.…”

Towards the drip lines of the nuclide landscape

“…The half-life for the β decay of 21 N is determined to be 82.9±7.5 ms which gave an accurate measured value so far [54]. Theoretical studies cover many different topics including cluster structures and decays [57][58][59][60][61][62], resonances in unstable nuclei [63][64][65], heavy and superheavy nuclei [66][67][68][69][70] (see [71] for the experimental synthesis of 271 Ds), rotational states [72][73][74][75][76][77][78][79][80], shape transitions [81][82][83], mean-field models [84][85][86][87], nuclear symmetry energy [88][89][90][91][92][93] and some other topics [94,95]. The theoretical works have motivated model developments, and also provided many useful theoretical predictions and explanations for the experiments.…”

Research program of superheavy elements and nuclides based on HIAF

“…[47][48][49] . 2 [50,51] ; 研制了先进的充气反冲核分离器和单 原子核鉴别测量系统, 验证性合成了110号元素的同 位素 271 Ds [52] . 此外, 我国核物理理论工作者深入开 展了超重核结构和产生机制研究 [19][20][21][53][54][55] .…”