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Fusing Nuclei Under Extreme Conditions

X-ray superbursts are fascinating phenomena in which an accreting neutron star emits the energy equal to the output of our sun in a century in just a few hours! The energy source fueling this explosive event is presently unknown. One possible source responsible is the fusion of neutron-rich nuclei, for example 24O + 24O → 48S, in the outer crust of the neutron star. Unlike the nuclear reactions driving our sun’s nuclear reactions however, these fusion reactions occur under conditions of low temperature and extremely high gravitational fields. A new generation of terrestrial radioactive beam facilities allow us to explore such reactions between neutron-rich nuclei at low temperature for the first time. A recent experiment by the deSouza group explores fusion between light neutron-rich nuclei in the sub-Coulomb barrier regime. Combined with advances in theoretical models these groundbreaking experiments promise to shed light on the fuel source for X-ray superbursts and to advance our understanding of how two nuclei fuse.

Read more: “Near- and sub-barrier fusion of 20O incident ions with 12C target nuclei,” Michael J. Rudolph, Zachary Q. Gosser, Kevin Brown, Sylvie Hudan, Romualdo T. de Souza, Abdou Chbihi, Bertrand Jacquot, Michael Famiano, J. Felix Liang, Dan Shapira, Damien Mercier, Physical Review 2012, C85, 024605.

Romualdo deSouza

Provost Professor