[Mesa-users] Calculation of Core Masses

[Bill Paxton]

Hi Chloe,

Good to hear from you.

Here’s a sketch of how to find what you want in the code.  At least this is how I went about it.

Knowing that the fe_core_mass is something that can go in history, i looked at history.f90 and found

            case(h_fe_core_mass)
               val = s% fe_core_mass

So someother piece of code has set s% fe_core_mass before the history output is called.
a grep in mesa/star/private for fe_core_mass shows points to report.f90.

the routine get_core_info in report calculates all of the core masses in a similar manner.  
For the case of the fe_core, it finds the outermost cell below the si_core with mass fraction of si28 < the specified fe_core_boundary_si28_fraction (default value of 0.01) and has sum of mass fractions with A >= A_max_fe (=47) >= min_boundary_fraction (default 0.1d0).    

so it isn’t just looking at a particular thing like Fe56.   It is looking for “enough” heavies as defined by A (defined in this case as number of protons plus number of neutrons rather than atomic weight).

hope that is helpful.

cheers,
bill





> On May 28, 2020, at 8:57 AM, Sandoval, Chloe via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Hi all,
> 
> I've been using MESA to create progenitors for CCSNe and I'm studying Silicon Shell burning in multi-D using MESA progenitors and another code, as well. I'm trying to make accurate comparisons of the growth of the iron core masses from both codes. I've found in the MESA I paper the definition for core masses: MESA star core masses are defined as the mass interior to the location where the element mass fraction is 0.5. However, if multiple species of iron are included in the network are they included in that mass fraction calculation?
> 
> I've been searching through the code and I can't seem to find where these are calculated. I've found all the logicals and the io for the core masses, but I can't find where in the code it's actually calculated. Can some point me in the right direction or tell me which fortran file the calculation is located in? I'm not looking to make changes to the code. I just need to make sure I'm defining/calculating the core masses the same way.
> 
> Thanks for your help!
> 
> Chloe Sandoval
> she, her, hers
> Graduate Research Assistant
> GSS Physics Department Representative
> Office: ORNL 4500S R211
> _______________________________________________
> mesa-users at lists.mesastar.org
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> 

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