1. New $\alpha$-Emitting Isotope $^{214}$U and Abnormal Enhancement of $\alpha$-Particle Clustering in Lightest Uranium Isotopes
- Author
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Zhang, Z. Y., Yang, H. B., Huang, M. H., Gan, Z. G., Yuan, C. X., Qi, C., Andreyev, A. N., Liu, M. L., Ma, L., Zhang, M. M., Tian, Y. L., Wang, Y. S., Wang, J. G., Yang, C. L., Li, G. S., Qiang, Y. H., Yang, W. Q., Chen, R. F., Zhang, H. B., Lu, Z. W., Xu, X. X., Duan, L. M., Yang, H. R., Huang, W. X., Liu, Z., Zhou, X. H., Zhang, Y. H., Xu, H. S., Wang, N., Zhou, H. B., Wen, X. J., Huang, S., Hua, W., Zhu, L., Wang, X., Mao, Y. C., He, X. T., Wang, S. Y., Xu, W. Z., Li, H. W., Ren, Z. Z., and Zhou, S. G.
- Subjects
Nuclear Experiment - Abstract
A new $\alpha$-emitting isotope $^{214}$U, produced by fusion-evaporation reaction $^{182}$W($^{36}$Ar, 4n)$^{214}$U, was identified by employing the gas-filled recoil separator SHANS and recoil-$\alpha$ correlation technique. More precise $\alpha$-decay properties of even-even nuclei $^{216,218}$U were also measured in reactions of $^{40}$Ar, $^{40}$Ca with $^{180, 182, 184}$W targets. By combining the experimental data, improved $\alpha$-decay reduced widths $\delta^2$ for the even-even Po--Pu nuclei in the vicinity of magic neutron number $N=126$ were deduced. Their systematic trends are discussed in terms of $N_{p}N_{n}$ scheme in order to study the influence of proton-neutron interaction on $\alpha$ decay in this region of nuclei. It is strikingly found that the reduced widths of $^{214,216}$U are significantly enhanced by a factor of two as compared with the $N_{p}N_{n}$ systematics for the $84 \leq Z \leq 90$ and $N<126$ even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the $\pi 1f_{7/2}$ and $\nu 1f_{5/2}$ spin-orbit partner orbits, which is supported by a large-scale shell model calculation.
- Published
- 2021
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