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Intermediate neutron-capture process (i process) on rapidly accreting white dwarfs

Stellar evolution models and nucleosynthesis analysis that show that rapidly accreting white dwarfs are very unlikely to reach Chandrasekhar mass, but instead produce i- process nucleosynthesis ejecta that may rival the production from s process in AGB stars for some elements.
Project summary
In this project, we propose a new site for the intermediate neutron-capture process. These are rapidly accreting white dwarfs in close binary systems. We also find that the mass retention efficiencies for CO white dwarfs that accrete H-rich matter at sufficiently high rates for stationary H burning are only a few per cent or even negative, which means that such white dwarfs are highly unlikely to reach the Chandrasekhar mass and explode as supernovae of type Ia.
About the simulation codes
We used the stellar evolution codes of MESA (revisions 5239 and 7624) to simulate the evolution of intermediate-mass stars from the pre-MS through to the white-dwarf cooling phase. The same codes were used to also simulate the evolution of the white dwarfs rapidly accreting H-rich matter from their close binary companions, with a rate of ~1e-7 solar masses per year that guaranteed stationary H-burning, followed by multiple He-shell flashes. Nucleosynthesis occurring during the He-shell flashes, including the i-process nucleosynthesis resulting from H ingestion by the convective He shell, was simulated using one of the NuGrid codes.
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Link to paper