[Triumf-seminars] TRIUMF Special Seminar today at 15:30

[postmaster at admin.triumf.ca]

Date/Time: Tue 2008-02-12 at 15:30

Location:  Auditorium          

Speaker:   Cody Folden (NSCL, Michigan State University)

Title:     Production of Transactinide Elements in Cold Fusion Reactions

Abstract: The transactinide elements are those beyond the actinide series and begin with rutherfordium (atomic number 104), which reconnects with the main body of the periodic table.  The most common reaction used to produce these elements is the complete-fusion, neutron-evaporation reaction, where the projectile is fused with the target to produce a compound nucleus with the momentum of the projectile.  Using shell-stabilized targets, compound nuclei with excitation energies of 10-20 MeV can be produced so that the evaporation of 1-2 neutrons is the most favorable exit channel.  These so-called "cold fusion" reactions were successfully used in the discoveries of elements 107-112 at GSI, and the recent production of element 113 at RIKEN.  In the case of odd-Z compound nuclei, where the odd proton can be in either the projectile or the target, measuring the excitation function of these two analogous reactions allows us to separate the role of the entrance channel on the total cross section.  This talk will discuss recent results on the production of darmstadtium, roentgenium, and bohrium in comparison with theoretical work on entrance channel effects, the role of the fusion barrier, and the selection of the optimum bombarding energy

Stimulants available 15 minutes before the talk. The speaker is a candidate for a professorship in the SFU chemistry department.

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