Search for the production of element 112 in the48Ca+238Ureaction

Abstract

We have searched for the production of element 112 in the reaction of 231 MeV 48 Ca with 238 U. We have not observed any events with a "one event" upper limit cross section of 1.6 pb for EVR-fission events and 1.8 pb for EVR-alpha events.

Multiple-humped fission and fusion barriers of actinide and superheavy elements

“…The analysis of the experimental data is discussed [9][10] . In the cold fusion reactions a wide potential pocket energy appears at large deformations and the inner peak is the highest for the heaviest systems.…”

Is E112 a relatively inert element? Benchmark relativistic correlation study of spectroscopic constants in E112H and its cation

“…The recent observation at FLNR (Dubna) of the "α-SF" chain, attributed to 4 sec α-decay branch of 283 112 followed by a 0.2 sec spontaneous fission of 279 110 (Ds) 2 , brought up the question, what species was observed in the previous "hot" fusion FLNR experiment 3 . Moreover, the production of 283 112 in the reaction of 48 Ca and 238 U was not confirmed at LBNL (Berkeley) 4,5 . However, a very specific decay mode of the short "α-SF" chain offered a unique chance to unambiguously identify 283 112 in a chemical experiment.…”

“…In scalar-relativistic CC-SD calculations, we have also estimated (see Table I 4 3/2 5d 6 5/2 6s 1 1/2 ) + H(1s 1 ). The 6p shell is closely localized to the 6d shell, therefore, the correlations between these shells have to be important for transitions with an essential change in the occupation number for the 6d shell.…”

Discovery of the Element with Atomic Number 112 (IUPAC Technical Report)

“…An independent repetition of the same experiment [30] did not show any events, albeit with insufficient sensitivity to disprove the data from [29].…”

“…Further experiments indicated a 4-s half life associated with a 9.5-MeV α-decay. But production attempts at Berkeley [30] failed to reproduce the observation. Chemistry experiments in Germany failed to observe the element with atomic number 112 [31].…”