[Mesa-users] Be9 burning

[Ebraheem Farag]

Hello Masanobu,

A more global solution, add the following to starjob "jina_reaclib_min_T9 =
2d-5". See
https://docs.mesastar.org/en/release-r24.03.1/reference/star_job.html#jina-reaclib-min-t9

"set jina reaclib rates to zero for T9 <= this. if this control is <= 0,
then use the standard default from rates. need <= 3d-3 for pre-ms li7
burning if change this, must remove old cached rates from
data/rates_data/cache"

Looking directly into $MESA_DIR/rates/public/rates_def.f90 to see how the
rates are tabulated, we find:
"

      *subroutine* do_start_rates_def_init(ierr)

         *use* math_lib

         *integer*, *intent*(*out*) :: ierr

         *integer* :: i

         ierr = 0

         *call* set_rattab_range(5.30102999566398d0, 10.301029995664d0)



         reaclib_min_T9 = 1d-2

            ! need <= 2d-3 for pre-ms li7 burning

            ! pre-ms deuterium burning needs much lower (4d-4)

            ! but that seems to cause problems during advanced burning.



      *end* *subroutine* do_start_rates_def_init
"

Lowering 'jina_reaclib_min_T9'  should solve the issue and ensure that all
your lowT reactions are not being set to 0.

-EbF

On Fri, May 3, 2024 at 1:21 PM Masanobu Kunitomo <
kunitomo.masanobu at gmail.com> wrote:

> Hi Ebraheem,
>
> Thank you for your comments and the file. From your file (and the attached
> plot), it is clear that the current version of MESA has Be9 burning rates
> only above 10 MK for some reason, which is insufficient.
> I made the attached table based on Caughlan & Fowler (1988), which gives
> the correct rates. Be9 is now burned at ~3.5 MK. Again thank you for your
> help!
>
> Best, -Masanobu
>
>
>
>
>
>
>
> > On May 2, 2024, at 21:43, Ebraheem Farag <ekfarag at asu.edu> wrote:
> >
> > Hello Masanobu,
> >
> > It seems that this is because the rate for 'r_h1_be9_to_h2_he4_he4' is
> only tabulated down to 10MK. You're seeing it turn on at the cusp of where
> the rate tabulation begins.
> >
> > by checking the rate in the rates module using :
> > "./show_rates
> $MESA_DIR/data/rates_data/cache/r_h1_be9_to_h2_he4_he4_1.bin >
> r_h1_be9_to_h2_he4_he4_1.txt"
> >
> > I was able to confirm, and I've attached a copy of the tabulated rate
> file that MESA produces in the most current version.
> >
> > -EbF
> >
> > On Thu, May 2, 2024 at 8:52 AM Masanobu Kunitomo via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
> > Dear MESA users,
> >
> > I am working on solar models and trying to see the evolution of the Be9
> abundance. Be9 should be burned at around 3.5 MK (e.g., Pinsonneault 1997)
> but the attached figure (1Msun star at the solar age) shows that it’s
> burned only in the core (> 1e7 K).
> >
> > I am using MESA ver. 12115 with the attached inlist files (based on
> Farag et al. 2020) w/ some modifications:
> >  add_isos(h3, be9, b10, b11, neut, li6)
> >  add_reaction(
> >     r_h1_be9_to_he4_li6
> >     r_he4_li6_to_h1_be9
> >     r_h1_be9_to_h2_he4_he4
> >     r_h2_he4_he4_to_h1_be9
> >     r_neut_be9_to_h3_li7
> >     r_h3_li7_to_neut_be9
> >     r_be9_to_neut_he4_he4
> >     r_neut_he4_he4_to_be9
> >     r_neut_b11_to_h3_be9
> >     r_h3_be9_to_neut_b11
> >     )
> >
> > I tried both choices of “rates_preference” (i.e., both NACRE and jina)
> but found no difference. I am not sure what is wrong/missing. Does anyone
> know how to calculate the Be9 abundance?
> >
> > Thank you in advance for any help.
> >
> > Best regards,
> > Masanobu
> >
> > --
> > Masanobu Kunitomo, Ph.D.
> > Department of Physics, Kurume University
> > 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
> > * Visiting researcher at Observatoire de la Côte d’Azur (Nov 2023–Oct
> 2024)
> > Email: kunitomo.masanobu at gmail.com
> >
> >
> >
> >
> >
> > _______________________________________________
> > mesa-users at lists.mesastar.org
> >
> https://urldefense.com/v3/__https://lists.mesastar.org/mailman/listinfo/mesa-users__;!!IKRxdwAv5BmarQ!bwoYVy7ENbqTAqqW3NhgTRMRYO64ehYcn2UV_2k6X-v9RBdVR8Im1y3xvOdMQwf-o8KDg5VwEGjE8PwiS2ZSxoqOuZizSQ$
> >
> > <r_h1_be9_to_h2_he4_he4_1.txt>
>
>
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