5 research outputs found
Ca-48+Bk-249 Fusion Reaction Leading to Element Z=117: Long-Lived alpha-Decaying (270)Db and Discovery of Lr-266
[Introduction] The superheavy element with atomic number
Z
¼
117
was produced as an evaporation residue in the
48
Ca
þ
249
Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The
radioactive decay of evaporation residues and their
α
-decay products was studied using a detection setup
that allowed measuring decays of single atomic nuclei with half-lives between sub-
μ
s and a few days. Two
decay chains comprising seven
α
decays and a spontaneous fission each were identified and are assigned
to the isotope
294
117
and its decay products. A hitherto unknown
α
-decay branch in
270
Db (
Z
¼
105
)
was observed, which populated the new isotope
266
Lr (
Z
¼
103
). The identification of the long-lived
(
T
1
=
2
¼
1
.
0
þ
1
.
9
−
0
.
4
h)
α
-emitter
270
Db marks an important step towards the observation of even more
long-lived nuclei of superheavy elements located on an
“
island of stability.
”peerReviewe