General Seminars

Perspectives for dense laser-driven ion beams in nuclear astrophysics

by Dr. Peter Thirolf (Ludwig-Maximilians University Munich)

Wednesday, 22 January 2014 from to (Europe/Bucharest)
at Măgurele ( National Library of Physics )
Description
Understanding the nucleosynthesis of heavy elements in the universe ranges amongst the key topics currently addressed in nuclear astrophysics. 'Waiting points' at closed nucleon shells play a crucial role in controlling the reaction rates. However, since most of the pathway of heavy-element formation via the rapid-neutron capture process (r-process) runs in 'terra incognita' of the nuclear landscape, in particular the waiting point at N=126 is yet unexplored and will remain inaccessible to conventional nuclear reaction schemes even at next-generation radioactive beam facilities.

Laser-induced ion acceleration at ELI-NP will offer the perspective to exploit the unique properties of laser-accelerated ion beams in order to explore the scenario of a new reaction mechanism based on ultra-dense ion bunches. Accelerating fissile species (e.g. 232Th) towards a second layer of the same material will lead to fission both of the beam-like and target-like particles. Due to the close to solid-state density of the accelerated ion bunches, fusion may occur between neutron-rich (light) fission products, thus opening a access path towards nuclides in the vicinity of the N=126 waiting point. The talk will outline the perspectives of this 'fission-fusion' mechanism and the required experimental conditions.