Laboratory Tests of Low Density Astrophysical Equations of State

TL;DR

This study experimentally investigates low-density nuclear matter using heavy-ion collisions, measuring densities and temperatures, and compares alpha particle production with astrophysical equations of state to constrain theoretical models.

Contribution

It provides new experimental data on nuclear matter densities and temperatures, and compares these with astrophysical equations of state to refine theoretical models.

Findings

Measured densities from 0.002 to 0.032 nucleons/fm³.

Temperatures ranged from 5 to 10 MeV.

Experimental alpha production constants compared with models.

Abstract

Clustering in low density nuclear matter has been investigated using the NIMROD multi-detector at Texas A&M University. Thermal coalescence modes were employed to extract densities, $\rho$, and temperatures, $T$, for evolving systems formed in collisions of 47 $A$ MeV $^{40}$Ar + $^{112}$Sn,$^{124}$Sn and $^{64}$Zn + $^{112}$Sn, $^{124}$Sn. The yields of $d$, $t$, $^{3}$He, and $^{4}$He have been determined at $\rho$ = 0.002 to 0.032 nucleons/fm$^{3}$ and $T$= 5 to 10 MeV. The experimentally derived equilibrium constants for $\alpha$ particle production are compared with those predicted by a number of astrophysical equations of state. The data provide important new constraints on the model calculations.