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Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh.

DE2008929699

Publication Date	2008
Personal Author	Nelson, S. L.
Page Count	171
Abstract	Several reactions producing odd-Z transactinide compound nuclei were studied with the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via different nuclear reactions. In doing so, it can be determined if there is a preference in entrance channel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's'Fusion By Diffusion' model is nearly identical for the two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs' cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrance channel in these paired reactions. Charge equilibration immediately prior to fusion leading to a decreased fusion barrier is the likely cause of this phenomenon.
Keywords	Alpha particles Transactinide compounds Nuclear reactions Angular momentum Bohrium Compound nuclei Cross sections Cyclotrons Decay Diffusion Excitation Nuclei Projectiles Protons Targets
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Berkeley National Lab., CA. Environmental Energy Technologies Div.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200824
Contract Number	DE-AC02-05CH11231

Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh.

Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh.
DE2008929699

Publication Date	2008
Personal Author	Nelson, S. L.
Page Count	171
Abstract	Several reactions producing odd-Z transactinide compound nuclei were studied with the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via different nuclear reactions. In doing so, it can be determined if there is a preference in entrance channel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's'Fusion By Diffusion' model is nearly identical for the two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs' cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrance channel in these paired reactions. Charge equilibration immediately prior to fusion leading to a decreased fusion barrier is the likely cause of this phenomenon.
Keywords	Alpha particles Transactinide compounds Nuclear reactions Angular momentum Bohrium Compound nuclei Cross sections Cyclotrons Decay Diffusion Excitation Nuclei Projectiles Protons Targets
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Berkeley National Lab., CA. Environmental Energy Technologies Div.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200824
Contract Number	DE-AC02-05CH11231