SAHA-S Equation of state
Version 3 of 9 Mar 2011
V.K.Gryaznov, I.L.Iosilevsky, A.N.Starostin

Download EOS tables (38.2 MB).

EOS tables are stored in several text files with thermodynamic values.
No interpolation routines are provided at the moment. Tables are rectangular
and have mesh evenly spaced in log10(T) and log10(Q),
here Q = rho/T6^2.25, T6=T/10^6. There are no gaps in the tables. Dimensions are:

log10(T): 3.20 ... 7.55, step 0.025
log10(Q): -4.50 ... 0.45, step 0.05
X: 0.1 ... 0.9, step 0.1
Z: 0.010, 0.015, 0.020

List of data files
------------------

Of 12 files available only first three are required to calculate
model of the solar internal structure. Other files contain
compositions which are not encountered inside the Sun. They are auxilarry
and may be available on request.

SunZ_010.re4 Z=0.01 (hydrogen + helium + heavy elements)
SunZ_015.re4 Z=0.015 (hydrogen + helium + heavy elements)
SunZ_020.re4 Z=0.02 (hydrogen + helium + heavy elements)

Sun0_H.re4 X=1, Y=0, Z=0 (pure hydrogen)
Sun0_He.re4 X=0, Y=1, Z=0 (pure helium)
Sun0_H_He.re4 Z=0 (hydrogen-helium mixture)

Sun_H_0_010.re4 X=0 Z=0.01 (helium + heavy elements, no hydrogen)
Sun_H_0_015.re4 X=0 Z=0.015 (helium + heavy elements, no hydrogen)
Sun_H_0_020.re4 X=0 Z=0.02 (helium + heavy elements, no hydrogen)

SunZ_He_0_010.re4 X=0.99 Y=0 Z=0.01 (hydrogen+heavy elements, no helium)
SunZ_He_0_015.re4 X=0.985 Y=0 Z=0.015 (hydrogen+heavy elements, no helium)
SunZ_He_0_020.re4 X=0.98 Y=0 Z=0.02 (hydrogen+heavy elements, no helium)

Data contents
------------------

All files have the same internal structure. Each file contains data
for one Z only (see description above). Files can contain data for
one X (again see description) or for X ranging from 0.1 to 0.9. First
line of each file is a header, the rest is data. Each line describes
one point by X, temperature, density. Columns are:

1 X hydrogen abundance
2 lgT log10 of temperature T, K
3 lnR natural log (rho/T6^3), T6=T/10^6, rho is density in g/cm^3
4 lgP log10 (pressure), pressure in bars, 1 bar = 10^6 g/(cm*s)
5 dlnPdlnRo partial derivative dlogP/dlog(rho), T=const
6 dlnPdlnT partial derivative dlogP/dlog(T), rho=const
7 dlnPdlnX partial derivative dlogP/dlog(X), T,rho=const
8 E internal energy, Joules/g, 1 Joule = 10^7 erg
9 dEdRo derivative dE/d(rho), Joules*cm^3/g
10 Cv specific heat at constant volume, Joules/(cm^3*K)
11 dEdX derivative dE/dX, Joules/g
12 S/R specific entropy S per gram divided by R, R is gas constant
13 ln Ne log (Ne), Ne is electron concentration in 1/cm^3
14 N_Tot Total particle concentration, 1/cm^3

Note that tables contain log(rho/T6^3), but mesh is evenly spaced in
log10(rho/T6^2.25). It is therefore suggested that interpolation be done
in log10(rho/T6^2.25).

Individual contents for heavy elements are according Asplund,
Grevesse, Sauval, Scott (2009). Elements taken into account:
H, He, C, N, O, Ne, Fe, Si Mg, S

References
----------

Please cite the following work when using these EOS tables:

V.K.Gryaznov, S.V.Ayukov, V.A.Baturin , I.L.Iosilevskiy, A.N.Starostin,
V.E.Fortov. Solar plasma: calculation of thermodynamic functions and
equation of state. Journal of Physics A: Mathematical and General,
v.39, 4459-4464, 2006.
DOI: 10.1088/0305-4470/39/17/S22