| 作者: |
Zhang, Z. Y.; Gan, Z. G.; Yang, H. B.; Ma, L.; Huang, M. H.; Yang, C. L.; Zhang, M. M.; Tian, Y. L.; Wang, Y. S.; Sun, M. D.; Lu, H. Y.; Zhang, W. Q.; Zhou, H. B.; Wang, X.; Wu, C. G.; Duan, L. M.; Huang, W. X.; Liu, Z.; Ren, Z. Z.; Zhou, S. G.; Zhou, X. H.; Xu, H. S.; Tsyganov, Yu. S.; Voinov, A. A.; Polyakov, A. N. |
| 摘要: |
A new short-lived neutron-deficient isotope Np-220 was synthesized in the fusion-evaporation reaction Re-185(Ar-40, 5n)Np-220 at the gas-filled recoil separator SHANS. Based on the measurement of the correlated alpha-decay chains, the decay properties of Np-220 with E-alpha = 10040(18) keV and T-1/2 = 25(-7)(+14 )mu s were determined, which are in good agreement with theoretical predictions. From the new experimental results coupled with the recently reported alpha-decay data of Np-219,Np-223, the alpha-decay systematics for Np isotopes around N = 126 was established, which allows us for the first time to test the robustness of the N = 126 shell closure in Z = 93 Np isotopes. The results also indicate that, in the region of nuclei with Z >= 83, the proton drip line has been reached for all odd-Z isotopes up to Np. |
