0000000001056770
AUTHOR
Rd Herzberg
α -decay spectroscopy of the N=130 isotones Ra 218 and Th 220: Mitigation of α -particle energy summing with implanted nuclei
An analysis technique has been developed in order to mitigate energy summing due to sequential short-lived α decays from nuclei implanted into a silicon detector. Using this technique, α-decay spectroscopy of the N=130 isotones Ra218 (Z=88) and Th220 (Z=90) has been performed. The energies of the α particles emitted in the Ra218→Rn214 and Th220→Ra216 ground-state-to-ground-state decays have been measured to be 8381(4) keV and 8818(13) keV, respectively. The half-lives of the ground states of Ra218 and Th220 have been measured to be 25.99(10) μs and 10.4(4) μs, respectively. The half-lives of the ground states of the α-decay daughters, Rn214 and Ra216, have been measured to be 259(3) ns and …
Production cross section and decay study of Es-243 and Md-249
In the study of the odd-Z, even-N nuclei Es-243 and Md-249, performed at the University of Jyvaskyla, the fusion-evaporation reactions Au-197(Ca-48, 2n)Es-243 and Tl-203(Ca-48, 2n) Md-249 have been used for the first time. Fusion-evaporation residues were selected and detected using a gas-filled separator coupled with its focal-plane spectrometer. For Es-243, the recoil decay correlation analysis yielded a half-life of 24 +/- 3 s and a maximum production cross section of 37 +/- 10 nb. In the same way, a half-life of 26 +/- 1 s, an alpha-branching ratio of 75 +/- 5%, and a maximum production cross section of 300 +/- 80 nb were determined for Md-249. The decay properties of Es-245, the daught…