[Mesa-users] White dwarf cooling for different compositions

[Na'ama Hallakoun]

Hi Rob and Héctor,

You are right - I edited to composition.dat file to:
2 11
0.00000 0.0 0.0 0.0 1 0.0 0 0.0 0.0 0 0 0
1.00000 0.0 0.0 0.0 1 0.0 0 0.0 0.0 0 0 0

and also changed the number of steps in the inlist:
      num_steps_to_relax_composition = 100 ! use this many steps to do
conversion

and now it runs for a few minutes, but stops prematurely. The last output
is:

                       avg remaining difference, lambda
1.1973214556606303D-01    7.0707070707070704D-02
       retry log10(dt/yr), log10(dt), retry_factor     1    11
-12.132556       -4.633444        0.500000
       retry log10(dt/yr), log10(dt), retry_factor     2    11
-12.433586       -4.934474        0.500000
 have reached retry limit so now backup
         10   7.261470  2.116E+04  -2.223732  -2.223732   0.607990
0.000127   0.000000   0.000000   0.234258   0.000083 196.862258   1429
31
 -12.132556   6.588016  -1.892029 -35.263752  -3.556724 -99.000000
0.607864   0.000000   0.516938   0.211484   0.017229  39.343151      3
15
 8.1574E+02  23.308977  -1.528510 -99.000000   3.802766  -4.475423
0.582739   0.462478   0.001493   0.000489  9.827E-01  0.184E+06
backup

                       avg remaining difference, lambda
1.1975161928679888D-01    7.0707070707070704D-02
       retry log10(dt/yr), log10(dt), retry_factor     1    11
-12.831526       -5.332414        0.500000
       retry log10(dt/yr), log10(dt), retry_factor     2    11
-13.132556       -5.633444        0.500000
 have reached retry limit so now backup
         10   7.261470  2.116E+04  -2.223732  -2.223732   0.607990
0.000127   0.000000   0.000000   0.234258   0.000083 196.862258   1429
33
 -12.831526   6.588016  -1.892029 -35.263752  -3.556724 -99.000000
0.607864   0.000000   0.516938   0.211484   0.017229  39.343151      3
16
 8.1574E+02  23.308977  -1.528502 -99.000000   3.802775  -4.475428
0.582739   0.462478   0.001493   0.000489  9.827E-01  0.918E+06
backup

                       avg remaining difference, lambda
1.1975161928679888D-01    7.0707070707070704D-02
       retry log10(dt/yr), log10(dt), retry_factor     1    11
-13.530496       -6.031384        0.500000
       retry log10(dt/yr), log10(dt), retry_factor     2    11
-13.831526       -6.332414        0.500000
                                                     dt
9.3028488155731540D-07
                                     min_timestep_limit
9.9999999999999995D-07

 stopping because of problems dt < min_timestep_limit

 do_relax_initial_composition ierr          -1
 do_star_job_controls_after ierr          -1
 before_evolve_loop ierr          -1

Héctor, thanks, I'll check out the link you sent!

Na'ama

On Mon, Jul 9, 2018 at 6:21 PM Rob Farmer <r.j.farmer at uva.nl> wrote:

> Hi
>
> The issue is that you need more than 8 isotopes in your composition.dat
> file, it must have the same number of isotopes as the nuclear network
> chosen. You can look in the wd_0.6.mod file (the model you are loading) and
> see that it uses 11 species so you need 11 columns and set the isotope
> count to 11.
>
> Rob
>
>
> On Mon, 9 Jul 2018 at 18:10, Héctor MR via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
>
>>   Hi Na'ama,
>>
>> The resulting abundance plot seems fine, but I don't see any difference
>>> in the cooling track when I edit the composition.dat file. What am I doing
>>> wrong?
>>>
>>
>>   Have you plotted the different cooling tracks altogether using any of
>> the MESA output tools (e.g. Bill Wolf's Python package), or are you looking
>> at the PGSTAR output from your various inlists, one after another? In
>> addition, are you sure that relax_initial_composition is working properly?
>> I would use the same number of shells that the model has, as well as more
>> steps to relax.
>>
>>
>>> In addition, the wd_cool_0.6M test uses a wd_0.6.mod model that starts
>>> from an effective temperature of ~17000K, so it messes up the age. How can
>>> I start from a hotter WD?
>>>
>>
>>   You can relax the initial mass of your model (
>> http://mesa.sourceforge.net/star_job_defaults.html#relax_initial_mass)
>> to get different physical conditions for the WD. If you really want to be
>> specific about your ages and composition, you can also create your own
>> pre-main sequence model (
>> http://mesa.sourceforge.net/star_job_defaults.html#create_pre_main_sequence_model)
>> and then evolve it until the WD cooling track. Although they correspond to
>> an older MESA version with no ne22 sedimentation, feel free to take a look
>> at my neutronization inlists (
>> http://cococubed.asu.edu/mesa_market/inlists.html), where I created WDs
>> and then stripped their envelopes, relaxed their initial masses...
>>
>>
>>   --
>>   H.
>> _______________________________________________
>> mesa-users at lists.mesastar.org
>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>
>>
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