[Mesa-users] problems with trace elements diffusion

[Ana Antonini]

Hi Morgan,

we set "do_element_diffusion" to true on our run_star_extras file so that
it only starts once the star is in the wd cooling track.
Diffusion is definitely happening, just not for the uranium.

thanks for taking the time to try to help though!

Morgan Taylor <taylormorgan32 at gmail.com> escreveu no dia quinta, 17/02/2022
à(s) 15:23:

> Hi Ana,
>
> I noticed that !do_element_diffusion =.true. is commented out in your
> inlist.
> In r-15140, the default is set to false.  Does your inlist_extra file set
> it to true?
> If not, diffusion won't be turned on, and your other diffusion controls
> will be ignored.
>
> Hope this helps,
>
> Morgan
>
> On Thu, Feb 17, 2022 at 10:53 AM Ana Antonini via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
>
>>
>> Dear Mesa users,
>>
>> We've been working on a project using MESA version r-15140 and have run
>> into a problem we can't seem to solve.
>>
>> We've been trying to investigate if the results from Horowitz & Caplan
>> (2021) can be reproduced with stellar evolution models, but despite trying
>> a broad combination of controls and parameters, we can't get our uranium
>> isotopes to actually diffuse.
>> Some of the things we tried:
>>
>>    -  setting a more rigorous tolerance for "diffusion_X_tot_atol" and
>>    "diffusion_X_tot_rtol"
>>    - forcing diffusion by setting "diffusion_class_factor" higher for
>>    the uranium species
>>    - limiting the timestep by using "diffusion_dt_div_timescale"
>>    - adding the timestep controls used in the wd_diffusion test_suite to
>>    our work
>>    - both using and not using the full net
>>    - setting the class_factor to zero for all classes except uranium
>>
>> I'm attaching our inlist as well as other pertinent files and would
>> greatly appreciate any ideas you might offer or even just a confirmation
>> that  MESA is indeed capable of doing diffusion for species with such a low
>> abundance.
>>
>> Kind  Regards,
>> A. Antonini
>> _______________________________________________
>> mesa-users at lists.mesastar.org
>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20220217/b531b6a2/attachment.htm>