[Mesa-users] Lithium and berylium evolution track

wan aishah wan harun easha_lampard at yahoo.com
Mon Feb 19 12:04:58 EST 2018

Thank you for the insight given.I will try to work it out

Many ThanksAishah

    On Monday, 19 February 2018, 23:56, amber lauer <amber.lauer at tunl.duke.edu> wrote:


On Sat, Feb 17, 2018 at 8:33 PM, Josiah Schwab via Mesa-users <mesa-users at lists.mesastar.org > wrote:

Hi Aishah,

> I want to know if there is a way I could produce li-7 and Be-8
> evolution tracks using MESA?  Please advise because I notice I can
> only display only certain abundances in the pgstar control.

​What do you mean you can only display certain abundances? I assume you are referring to the abundance plot, but you can display any isotope in the net.​ If you open the file /mesa/star/defaults/pgstar. defaults, and locate the section for the abundance window, you'llsee that you can specify any isotope using the commands
   Abundance_num_isos_to_show = 4         Abundance_which_isos_to_show( 1) = 'h1'         Abundance_which_isos_to_show( 2) = 'he3'         Abundance_which_isos_to_show( 3) = 'he4'         Abundance_which_isos_to_show( 4) = 'c12'
​Note that these are just examples to show you the format. Again, any isotope in the net can be shown this way. Another important note: if you leave the abundance window to its own devices it will display the most abundant isotops (anyone know how many by default?). This in itself is not unusual but the "most abundant" isotopes can change, which means when they do MESA will change the color code for each abundance, which some people find confusing. So even if the "most abundant isotope" scheme is enough for your needs it might be useful to try the other method just for clarity.  ​
You can display any abundances that are included in the MESA stellar
model in pgstar.  If you want to study these isotopes you should make
sure they are a part of your nuclear network.

You can change the nuclear network with the control

  http://mesa.sourceforge.net/st ar_job_defaults.html#change_ne t

and there is information about the nuclear networks in the files

  $MESA_DIR/data/net_data/nets/R EADME
  $MESA_DIR/data/net_data/NET_NO TES

The network pp_extras.net extends the basic network by adding h2, li7,
be7, b8, so that seems like what you might want.

Given its short lifetime, nets essentially never explicitly include
Be-8, though it is implicitly included in relevant reaction chains
(i.e. triple alpha, PP III).

Hope that helps,
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Amber LauerPostdoctoral ResearcherTriangle University Nuclear LabDuke Universityamber.lauer at tunl.duke.edu

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