摘要
A radioactive nucleus is characterized with an intrinsic half-life. However, for a nuclear species, the half-lives inneutral atoms could be very different from that in highly charged ions. The half-lives of some highly charged ionshave been directly measured at GSI for multiple motivations[1]. In the same case, the nuclear state(i:e the isomer)may be in the range of several tens of microseconds and their half-live can be measured using isochronous massspectrometry. The J = 8+ isomeric state in 94Ru was chosen to test this method. The half-life of this isomer is71 s [2] in neutral atoms, and the excitation energy is 2.64 MeV. The internal conversion coefficient of this decayin neutral atom is 0.335. So its half-life in the bare nucleus would be modified to be 94.78 s when the internalconversion channel is blocked.
