W. Loveland

Search for the production of element 112 in the 48Ca+238U reaction

Author(s): Loveland, Walter; Gregorich, Ken; Patin, Joshua B.; Peterson, D.; Rouki, C.; Zielinski, Peter M.; Aleklett, K.

Evidence for the possible synthesis of element 110 produced by the {sup 59}Co+{sup 209}Bi reaction

An experiment to synthesize element 110 by the {sup 59}Co+{sup 209}Bi reaction has been performed at the SuperHILAC at the Lawrence Berkeley Laboratory. One event with many of the expected characteristics of a successful synthesis of {sup 267}110 was observed. This event corresponds to a production cross section of about one picobarn.

Superheavy elements: a crossroads.

The failure to synthesize superheavy elements by using complete fusion reactions is most likely understandable in terms of the low survival probabilities of the superheavy precursors formed in these reactions or (in some cases) the failure to achieve complete fusion. Further attempts to synthesize these elements by using complete fusion or deep inelastic transfer reactions, or both, are discussed in light of these results.

Evidence for the synthesis of 267110 produced by the 59Co+209Bi reaction

Abstract An experiment to synthesize element 110 by the 59 Co+ 209 Bi reaction has been performed at the SuperHILAC at the Lawrence Berkeley Laboratory. One event with many of the expected characteristics of a successful synthesis of 267 110 was observed. This event corresponds to a production cross section of about one picobarn.

Cross-section limits for the 208Pb(86Kr, n) 293118 reaction

Abstract.In April-May, 2001, the previously reported experiment to synthesize element 118 using the 208Pb(86Kr,n)293118 reaction was repeated. No events corresponding to the synthesis of element 118 were observed with a total beam dose of 2.6 x 1018 ions. The simple upper-limit cross-sections (1 event) were 0.9 and 0.6 pb for evaporation residue magnetic rigidities of 2.00 Tm and 2.12 Tm, respectively. A more detailed cross-section calculation, accounting for an assumed narrow excitation function, the energy loss of the beam in traversing the target and the uncertainty in the magnetic rigidity of the Z = 118 recoils is also presented. Re-analysis of the primary data files from the 1999 experiment showed the reported element 118 events are not in the original data. The current results put constraints on the production cross-section for synthesis of very heavy nuclei in cold-fusion reactions.

The

The yields of over 200 projectile-like fragments (PLFs) and target-like fragments (TLFs) from the interaction of (E

^{136}

_{c.m.}

Xe +

=450 MeV)

^{208}

^{136}

Pb reaction: A test of models of multi-nucleon transfer reactions

Xe with a thick target of