Limits of thermonuclear synthesis at extreme conditions of supernovae and neutron star binaries

One of the greatest questions of astrophysics is what is the mechanism for synthesis of heavy elements beyond Iron.

The leading theory supported by astronomical spectroscopy data is the R-process, rapid neuton capture thermonuclear reaction.

The conditions for R-process require extreme temperatures of billions of Kelvins, and extremely dense neutron-rich matter as close as those of neutron stars.

Such kind of conditions occur at core collapse supernova, neutron star binary systems, and black hole bineries.

In my years as a PhD researcher at Oak Ridge National lab, I had to study the limits of the R-process, i.e. the stability of heaviest isotopes and elements in nature, which can be generated by R-process.
The study was done by me and by using the most powerful supercomputer in the world at that time, "Jaguar" at Oak Ridge National laboratory.

The results showed, that at certain atomic masses limits, R-process competes with the spontaneous nuclear fission, which acts like a break for the thermonuclear synthesis. In my talk, we will dive into the extreme conditions where nuclear fusion and nuclear fission compete head-to-head each other during supernova events and neutron star (black hole) binaries.
What determines the isotope stability against nuclear fission are the quantum mechanical effects inside nuclei.

The Quantum Mechanics of atoms, protons, and neutrons is the major player into these large-scale cosmic catastrophic events.

Speaker: Dr. Nikola Nikolov