pynucastro.networks.nse_network module

pynucastro.networks.nse_network module#

A collection of classes and methods for working with nuclear statistical equilibrium.

class pynucastro.networks.nse_network.NSENetwork(*args, use_unreliable_spins=True, **kwargs)[source]#

Bases: RateCollection

A network for solving the NSE composition and outputting tabulated NSE quantities

generate_table(rho_values=None, T_values=None, Ye_values=None, comp_reduction_func=None, verbose=False, outfile='nse.tbl')[source]#

Generate a table of NSE properties. For every combination of density, temperature, and Ye, we solve for the NSE state and output composition properties to a file.

Parameters:

  • rho_values (numpy.ndarray) – values of density to use in the tabulation

  • T_values (numpy.ndarray) – values of temperature to use in the tabulation

  • Ye_values (numpy.ndarray) – values of electron fraction to use in the tabulation

  • comp_reduction_func (Callable) – a function that takes the NSE Composition object and returns a new Composition representing a reduced set of nuclei.

  • verbose (bool) – output progress on creating the table as we go along

  • outfile (str) – filename for the NSE table output

get_comp_nse(rho, T, ye, init_guess=(-3.5, -15), tol=1e-11, use_coulomb_corr=False, return_sol=False)[source]#

Return the NSE composition given density, temperature and prescribed electron fraction using scipy.fsolve.

Parameters:

  • rho (float) – NSE state density

  • T (float) – NSE state Temperature

  • ye (float) – prescribed electron fraction

  • init_guess ((tuple, list)) – initial guess of chemical potential of proton and neutron, [μ^{id}_p + μ^{c}_p, μ^{id}_n]

  • tol (float) – tolerance of scipy.fsolve

  • use_coulomb_corr (bool) – whether to include coulomb correction terms

  • return_sol (bool) – whether to return the solution of the proton and neutron chemical potential.

Returns:

  • comp (Composition) – the NSE composition

  • u (ndarray) – the chemical potentials found by solving the nonlinear system.

class pynucastro.networks.nse_network.NSETableEntry(rho, T, Ye, *, comp=None, ydots=None, enu=None, comp_reduction_func=None)[source]#

Bases: object

A simple container to hold a single entry in the NSE table.

Parameters:

  • rho (float) – the density of the NSE state

  • T (float) – the temperature of the NSE state

  • Ye (float) – the electron fraction

  • comp (Composition) – the NSE composition

  • ydots (dict) – a dictionary of dY/dt keyed by Nucleus. This is meant to be the weak nuclear rates only, since those affect the NSE state.

  • enu (float) – the weak rate neutrino energy loss

  • comp_reduction_function (Callable) – a function that converts the NSE composition into a smaller set of nuclei. It takes a Composition object and returns a new Composition object representing the reduced set of nuclei and their abundances.

value()[source]#

Return an integer used for sorting. This has the format (logrho)(logT)(1-Ye)