[Mesa-users] Be9 burning

[Masanobu Kunitomo]

Hello Ebraheem,

Thank you very much for the information. I have tried a simulation with "jina_reaclib_min_T9 = 2d-5”, after removing the tabulated rate files and old rates_cache files, and I found it works! Also I found that this is a better solution because be9 was slightly more burned probably because other reactions also worked (e.g., r_h1_be9_to_he4_li6).
Now I understand that the issue came from this control and the Be9 burning rate in MESA has no problem.
Again thank you very much for your kind help!

Cheers, -Masanobu




> On May 4, 2024, at 22:44, Ebraheem Farag <ekfarag at asu.edu> wrote:
> 
> 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>
>