[Mesa-users] Building He layer in ns_h test suite problem

[Frank Timmes]

hi david,

interesting observation.

this test suite case dates from ~2012 and version 4161 when mdot was 1e-11 msun/yr with a 0.75 h, 0.24 he composition. by version 12778, mdot was 1.7e-11 msun/yr with the same composition. starting with version 15140 the single inlist was split into multiple inlists with the first being the buildup of a he envelope with  mdot = 1e-9 msun/yr.

i cannot locate or remember a reason for this last value of mdot, but maybe someone can correct me. i doubt it was to stress test parts of mesa. 

fxt




> On Dec 5, 2023, at 1:30 PM, David Neto via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> 
> Hello all,
> 
> In the ns_h test suite problem during the first part of the simulation (inlist_add_he_layer), was there a specific reason or motivation for the accretion rate used during this part of the simulation? With the default values, Mdot is 1E-9 Msun/yr, and you simulate for 0.5 seconds, which gives lots of retries and a fairly long compute time when run. If one cuts mdot in half and doubles the simulation time (so, building up the same outer helium layer mass), the number of retries and computation time drops dramatically. This is all in preparation for the second step, testing steady hydrogen burning.
> 
> I was just wondering if this choice of parameters in the test suite was to "stress test" parts of MESA or if there was another astrophysical reason for the choice of mdot and simulation time.
> 
> For reference, this is using MESA version 23.05.1 and MESA SDK version 22.6.1.
> 
> Cheers,
> David
> 
> 
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