English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We compute the structure of a Newtonian, multi-ion radiation-mediated shockfor different compositions anticipated in various stellar explosions, includingsupernovae, gamma-ray bursts, and binary neutron star mergers, using amulti-fluid RMS model that incorporates a self-consistent treatment ofelectrostatic coupling between the different plasma constituents. We find asignificant velocity separation between ions having different charge-to-massratios in the immediate shock downstream and demonstrate that in fast enoughshocks ion-ion collisions can trigger fusion and fission events at a relativelylarge rate. Our analysis does not take into account potential kinetic effects,specifically, anomalous coupling through plasma microturbulence, that cansignificantly reduce the velocity spread downstream, below the activationenergy for nuclear reactions. A rough estimate of the scale separation in RMSsuggests that for shocks propagating in BNS merger ejecta, the anomalouscoupling length may exceed the radiation length, allowing a considerablecomposition change behind the shock via inelastic collisions of $\alpha$particles with heavy elements at shock velocities $\beta_u\gtrsim0.2$.Moreover, a sufficient abundance of free neutrons upstream of the shock canalso trigger fission through neutron capture reactions downstream. Theresultant change in the composition profile may affect the properties of theearly kilonova emission. The implications for other exploding systems are alsobriefly discussed.

Fission and fusion of heavy nuclei induced by the passage of a radiation-mediated shock in BNS mergers