[Mesa-users] Electron Capture in High Density Regimes

[Joseph Hellmers]

Thanks Josiah.

Using the simulation wd_c_core_ignition as a starting point, I added the star_job settings you recommended and ran the model, but I didn’t see any difference in the LOGS/profileNN.data files or in history.data.  Where should I see the additional reaction network information?

BTW this simulation uses approx21.net I think (new_net_name = 'approx21.net’).


> On Feb 1, 2021, at 1:34 PM, Josiah Schwab <jwschwab at ucsc.edu> wrote:
> 
> Hi Joe,
> 
> Does MESA include electron captures, i.e. inverse beta decay, in its reaction calculations?  I can see from the docs, 
> 
> https://docs.mesastar.org/en/latest/reference/star_job.html?highlight=beta#use-suzuki-weak-ratesthere
> 
> there are provisions for using special rates, but I’m wondering if there is a particular reaction library that most be chosen, so some other configuration that must be used to include them.
> 
> MESA includes electron capture reactions if the nuclear network includes the relevant isotopes and reactions (and if we have rate data for that reaction).
> 
> You can see the isos and reactions in your net with the star job flags
> 
>     show_net_species_info = .true.
>     list_net_reactions = .true.
> 
> In some cases you may need to add isotopes/reactions to your network to get what you want.  For example, ne23, the neutron-rich daughter of na23 is often not in nets by default since the high density conditions where it's relevant aren't typical.
> 
> You can set the standard MESA collection of weak rates in data/rates_data/weakreactions.tables (plus the weak reactions that are in JINA REACLIB).
> 
> The Suzuki et al. (2016) rates replace the default collection of rates for the sd-shell nuclei with a more densely tabulated set, which is especially important in cooler conditions.   (I'm guessing you're interested in Mch WDs, so you probably do want to use these.)
> 
> I can give more detailed advice if you have a specific application in mind.
> 
> Josiah