[Mesa-users] Scaling Triple Alpha Rate

[Aaron Dotter]

Hi Mitchell,

The problem with your inlist is that you're not using the correct name for
the reaction.

It should be r_he4_he4_he4*_to_*c12 and you should get immediate
notification that you're using a special rate.  Unfortunately, this is a
case where using a reaction name that doesn't exist "fails quietly".


                                         version_number       11701
 create pre-main-sequence model
       set special rate factor for r_he4_he4_he4_to_c12           6
 1.1000000000000001D+00
       set special rate factor for r_he4_he4_he4_to_c12           6
 1.1000000000000001D+00
                                          species  mass           8
 1.6999999999999997D+00

Aaron



On Sat, Nov 13, 2021 at 9:18 PM Mitchell Dennis <mtde226 at hawaii.edu> wrote:

> Dear MESA Users,
>
>
>
> Apologies for the double email. I accidentally sent my email before I
> finished drafting it.
>
> I am having trouble using the following star_job parameters to scale the
> triple alpha rate.
>
> num_special_rate_factors=1
>
> reaction_for_special_factor(1)='r_he4_he4_he4_c12'
>
> special_rate_factor(1)=1.1d0
>
> I tried using both ‘r_he4_he4_he4_c12’ and ‘tri_alfa’ to modify the
> reaction rate and neither yielded any change in the model outputs. To check
> to make sure there was no change, I checked the he_power, surface gravity,
> effective temperature, and final metallicity from the history columns
> output. Each of these were identical no matter which value I used for
> ‘special_rate_factor(1)’ and even if the parameters were commented out in
> my inlist. I have attached my inlist to this email. I am using MESA version
> 12778 to see the effect of the triple alpha rate on the tip of the red
> giant branch.
>
>
>
> Best Regards,
>
> Mitchell T Dennis
>
> Graduate Student
>
> University of Hawaii – Institute for Astronomy.
>
>
> _______________________________________________
> mesa-users at lists.mesastar.org
> https://lists.mesastar.org/mailman/listinfo/mesa-users
>
>
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