The decay of the 13/2⁺ isomeric state in ¹⁸³Hg was observed for the first time following the α decay of the 13/2⁺ isomer in ¹⁸⁷Pb produced in the ¹⁴²Nd(⁵⁰Cr, 2p3n) reaction. Using $\alpha -\gamma$ delayed coincidence measurements, the half-life of this isomer was measured to be 290(30) μs. This isomer is proposed to deexcite by an unobserved low-energy M2 transition to the known 9/2⁻ member of a strongly prolate-deformed 7/2⁻[514] band, followed by a 105-keV M1 transition to the bandhead. A lower limit of B(M2) ≥ 0.018 W.u. was deduced for the unobserved transition. The presumed retardation is proposed to be due to the notable shape change between the initial, nearly spherical, and the final, strongly deformed, states. A similar scenario is also considered for the 13/2⁺ isomer in ¹⁸¹Hg, suggesting both are cases of shape isomers. The $B(M2)$ systematics of neutron transitions across the nuclear chart is discussed.

^在142 Nd( ⁵⁰ Cr, 2p3n) 反应生成的¹⁸⁷ Pb中的 13/2 ⁺异构体发生α衰变后，首次观察到¹⁸³ Hg 中13/2 ⁺异构体的衰变。使用$\alpha -\gamma$延迟符合测量，该异构体的半衰期测量为 290(30) μs。该异构体被提议通过未观察到的低能M 2 跃迁到已知的 9/2 ^-强烈长形变形 7/2 ^- [514] 带的成员来去激发，然后是 105-keV M 1 跃迁到带头. 对于未观察到的跃迁，推导出B ( M 2) ≥ 0.018 Wu的下限。推测的延迟被认为是由于初始的近球形状态和最终的强烈变形状态之间的显着形状变化。^{181中的 13/2 +}异构体也考虑了类似的情况Hg，表明两者都是形状异构体的情况。这$乙(米2)$讨论了整个核图的中子跃迁系统学。