NSE abundance data

TL;DR

This paper introduces a novel, efficient method for calculating Nuclear Statistical Equilibrium (NSE) abundances that is adaptable, faster for large networks, and requires less data storage, with broad applications in astrophysics simulations.

Contribution

The paper presents a new interpolation-based approach for NSE calculations that improves speed, flexibility, and compatibility over traditional Newton-Raphson methods, especially for large nuclear networks.

Findings

Method is faster than traditional NSE solvers for large networks.

Requires minimal stored data, only two large tables.

Works well with random inputs and does not need initial guesses.

Abstract

Novel method of calculating Nuclear Statistical Equilibrium is presented. Basic equations are carefully solved using arbitrary precision arithmetic. Special interpolation procedure is then used to retrieve all abundances using tabulated results for neutrons and protons, together with basic nuclear data. Proton and neutron abundance tables, basic nuclear data and partition functions for nuclides used in calculations are provided. Simple interpolation algorithm using pre-calculated p and n abundances tabulated as a functions of kT, rho and Ye is outlined. Unique properties of this method are: (1) ability to pick-up out of NSE selected nuclei only (2) computational time scaling linearly with number of re-calculated abundances (3) relatively small amount of stored data: only two large tables (4) slightly faster than solving NSE equations using traditional Newton-Raphson methods for small networks (few tens of species); superior for huge (800-3000) networks (5) do not require initial guess; works well on random input (6) can tailored to specific application (7) ability to use third-party NSE solvers to obtain fully compatible tables (8) encapsulation of the NSE code for bug-free calculations. Range of applications for this approach is possible: coverage test of traditional NSE Newton-Raphson codes, generating starting values, code-to-code verification and possible replacement of the old legacy procedures in supernova simulations.