The fusion of $^{11}$Li with $^{208}$Pb
ORAL
Abstract
We studied the fusion of $^{11}$Li with $^{208}$Pb at TRIUMF. The intensity of the $^{11}$Li beam (chopped) was 1000 p/s and the beam on-target time was 114 hours. The stacked foil technique was used to step the beam energies from 40 to 29 MeV (E$_{c.m.}$ = 27-38 MeV) throughout the array. The $\alpha$-decay of the stopped EVRs was detected in a $\alpha$-detector array at each beam energy in the beam-off period. The geometrical efficiency of detection of the decay $\alpha$-particles has been calculated to be 0.4. To verify this, we measured the evaporation residue yield for the well-known $^{7}$Li + $^{209}$Bi reaction. We have previously measured the evaporation residue cross sections when $^{9}$Li, the $^{11}$Li core, fuses with $^{208}$Pb. We also have done HIVAP calculations of what we might expect for evaporation residue cross sections if $^{11}$Li were to fuse with $^{208}$Pb rather than breakup. The At isotope patterns observed on-line are not those observed for the $^{9}$Li + $^{208}$Pb reaction but are consistent for expectations of complete fusion.
*This work was supported, in part, by the USDOE, Office of Nuclear Physics, under Grant No. DE-FG06-97ER41026
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