Coulomb dissociation of $^{20,21}$N

TL;DR

This study measures Coulomb dissociation of neutron-rich nitrogen isotopes to derive neutron capture rates, revealing significant differences from theoretical models that impact fluorine abundance predictions in astrophysics.

Contribution

The paper provides experimental data on Coulomb dissociation of $^{20,21}$N, enabling more accurate neutron capture rates relevant for astrophysical nucleosynthesis.

Findings

$^{19}$N(n,γ)$^{20}$N rate is up to 5 times higher at T<1 GK

Revised reaction rates decrease predicted fluorine abundance by 10%

Experimental data improves understanding of neutron-rich light nuclei reactions

Abstract

Neutron-rich light nuclei and their reactions play an important role for the creation of chemical elements. Here, data from a Coulomb dissociation experiment on $^{20,21}$N are reported. Relativistic $^{20,21}$N ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the $^{19}\mathrm{N}(\mathrm{n},\gamma)^{20}\mathrm{N}$ and $^{20}\mathrm{N}(\mathrm{n},\gamma)^{21}\mathrm{N}$ excitation functions and thermonuclear reaction rates have been determined. The $^{19}\mathrm{N}(\mathrm{n},\gamma)^{20}\mathrm{N}$ rate is up to a factor of 5 higher at $T<1$\,GK with respect to previous theoretical calculations, leading to a 10\,\% decrease in the predicted fluorine abundance.