[Triumf-seminars] TRIUMF Theory Seminar today at 13:00

[TRIUMF Seminars]

Date/Time: Tue 2013-12-03 at 13:00

Location:  Theory Room         

Speaker:   Jeremy Dohet-Eraly (TRIUMF)

Title:     Describing the nucleus-nucleus bremsstrahlung by a microscopic cluster approach

Abstract: Nucleus-nucleus bremsstrahlung is a radiative transition between continuum states, where the photon emission is induced by a collision between two nuclei or a nucleus and a neutron. It is an interesting tool for studying the cluster structure of the unbound states and is also interesting by itself, particularly since the perspective of using the t(d,n gamma)alpha bremsstrahlung to diagnose plasmas in fusion experiments.

In this talk, I present a microscopic cluster model of bremsstrahlung based on an extension of the Siegert theorem, i.e. based on the charge density rather than on the current, which allows including implicitly a part of the effects of meson-exchange currents.  The collision wave functions are derived from a microscopic Schrödinger equation based on an effective nucleon-nucleon (NN) interaction with one or two parameters adjusted to elastic data only. Simple cluster wave functions, which are consistent with this NN interaction, are considered. The model is applied to the alpha+alpha and alpha+N systems at low photon energy for which experimental data are available. The importance of the meson-exchange currents, which are included by the Siegert approach, is analyzed for both E1 and E2 transitions.

An extension of this model towards an ab initio approach, based on a realistic NN interaction and the description of the collision wave functions by the no-core shell model/resonating-group method, is briefly discussed.





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