Speaker
Description
In-beam $\gamma$-ray spectroscopy experiments on the heavy odd-$Z$ nuclei $^{249}$Md and $^{251}$Md were performed at the ATLAS accelerator facility of Argonne National Laboratory using the $^{203}$Tl($^{48}$Ca, 2$n$) and $^{205}$Tl($^{48}$Ca, 2$n$) fusion evaporation reactions, respectively. In both experiments the Argonne Gas-Filled Analyzer (AGFA) was used to separate recoils of interest, while Gammasphere detected prompt $\gamma$-rays emitted from excited states and the X-array provided sensitivity to isomeric states and decays.
Recoil- and recoil-decay tagging techniques were utilised to identify new rotational bands in $^{249}$Md based on one-proton quasiparticle states. One observed set of states forms a pair of strongly coupled bands with relatively strong E2 transitions, and another sequence of $\gamma$-ray transitions is indicative of a decoupled band of E2 transitions. These bands are respectively assigned as based on the Nilsson level configurations 7/2$^{-}$[514] and 1/2$^{-}$[521], corresponding to the ground and first excited state of $^{249}$Md. The presence of at least one high-$K$ multi-quasiparticle isomer was also confirmed in $^{249}$Md. This talk presents the results of the $^{249}$Md experiment, and a discussion of preliminary findings from the experiment on $^{251}$Md.
This work was supported, in part, by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-05CH11231 (LBNL), Contract No. DE-AC02-98CH10886 (BNL). This work is funded by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357 (ANL). This research used resources of Argonne National Laboratory’s ATLAS facility, which is a DOE Office of Science User Facility.
| Contribution category | Experiment |
|---|---|
| Presenter status | Postdoc |