[mesa-users] mesa version 6596 is now available

[Bill Paxton]

mesa version 6596 is now available.   here is an outline of the changes since the last release (6208, March 24)

-Bill



Frank and Bill -- rates and nets

introduce new mesa family of "soft" nets (i.e., defined by giving set of isotopes; system picks reactions)
net names are "mesa_N.net" where N is number of isotopes.  
current choices for N are 78, 125, 160, 201, 495, 833, 1508, and 3335.

prune the collection of hardwired nets.   here's the new set of standard ones.
basic
   basic_plus_fe56
   basic_plus_fe56_ni58
   o18_and_ne22
   o18_to_mg26
   c13
pp_extras
   pp_extras_plus_be9
cno_extras
   cno_extras_plus_fe56
   cno_extras_o18_and_ne22
   cno_extras_o18_to_mg26
   cno_extras_o18_to_mg26_plus_fe56
hot_cno
pp_and_cno_extras
   pp_and_cno_extras_o18_ne22
agb
   sagb_NeNa
   sagb_NeNa_MgAl
co_burn
   co_burn_plus
   co_burn_extras
   ecapture
approx21

create a new family of approx21 nets with choice for neutron-rich isotopes other than cr56.
names are "approx21_ISO.net" where ISO is one of cr56 to cr66, mn56, or mn57.

reimplement approx21 for better performance and numerical stability using Frank's code as basis.
introduce quad precision calculation of dydt

remove high T reaction rate limits. 
can now run fully coupled approx21 models to core collapse without it.
but note that we still have high T limits on convective coeffs

currently changing one-zone burn implementation.  use with caution for now.


Pablo -- binaries

Removed fixed mass to turn off jdot_mb, added flag to keep it always on
Use mass of stellar models in binary initialization to deal properly with loaded models
Fix initialization of accretor roche lobe radius
Avoid use of photosphere_r in binary, as it is not resetted for redos and retries
Fix lag in lg_mstar_dot_2 when using evolve_both_stars = .true.
use alpha, beta, delta notation for mass transfer efficiency
Improve donor switch and set as default
cleanup tides
modify implicit scheme to fix precision in mass transfer rate
add custom varcontrols for different stages
included eccentricity (thanks to Joris Vos)
set binary switch off by default for now
fix problem with fixed donor setting
fixed mass to turn off jdot_mb, added flag to keep it always on


Rich -- GYRE

Updated mesa to GYRE 3.1.2.  requires new mesa sdk


Josiah -- ecapture

Allow ecapture to work along with other weak rates

A bug in the logic of the ecapture rate code meant that the modified
ecapture weak rates could not be used when other weak rates (provided by
weaklib) were in the network.

The code now checks to see if the desired rate can be calculated by the
ecapture code, and if it can be, it does so.  That means that at
present, a user must either use all of the ecapture rates or none of
them.  A work around is to edit the files ecapture_states.list and
ecapture_transitions.list to only include the desired transitions.

Revise test of electron capture reactions

The previous test compressed (via accretion) a realistic ONeMg white
dwarf and checked that the run terminated due to the center reaching a
certain temperature (because of heating from electron-captures) before a
reaching certain density.  This test had been broken since r6472.

The new test compresses (via accretion) an unrealistic white dwarf
composed of 100% Mg-24.  The test now uses run_star_extras.f to confirm
that Mg-24 has been converted to Ne-24 before reaching a central density
significantly above the threshold density for the captures.  It also
checks that the central temperature has increased by an appropriate
amount due to the entropy generation from the captures.


Misc.

add "initial" versions of some controls in star job. 
e.g., relax_initial_tau_factor and set_initial_tau_factor in addition to existing controls relax_tau_factor and set_tau_factor

thanks to Konstantin Pavlovskii for correction to Pextra in mod_atm
add control Pextra_factor for atm grey.   note: the correction breaks some of the star test cases!  e.g., 90M_z2m2_high_rotation.
someday someone will figure out why; for now the correction can be disabled by setting Pextra_factor negative.  

add vars for mlt results saved at start of step. all mlt results updated at each call (as before).
e.g., mlt_mixing_type_start has value from start of step, while mlt_mixing_type has value from end of step.

incorporate patches from Broxton Miles in adjust_mass and evolve

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