[mesa-users] mesa 4930

[Bill Paxton]

Hi,


Last release introduced some large changes to diffusion, and now this one has some bug fixes for that.
Rich Townsend noticed that the "bump" in the RGB was being erased by diffusion; now it is back.
So if you are a user of diffusion, don't skip this revision.


It also has changes to defaults discussed in the series of emails initiated by Tug.

	prune_bad_cz_min_Hp_height now defaults to 0
	remove_mixing_glitches is still .true., 
	but all the cases are disabled except for okay_to_remove_mixing_singleton.


Thanks to help from Victor Silva Aguirre, we now have an option to use the Langer et al 1985 formula for
semiconvective temperature gradient in addition to using their mixing scheme.  We still have the option
to use the radiative temperature gradient of course.  The new control is "semiconvection_option".

         semiconvection_option = 'Langer_85 mixing; gradT = gradr'
            ! 'Langer_85 mixing; gradT = gradr' -- uses Langer scheme for mixing but sets gradT = gradr
            ! 'Langer_85' -- this calculates special gradT as well as doing mixing.


If you use the "approx21" net, you know it includes a fake electron capture reaction from ni56 to cr56 that serves
to mimic late stage neutronization.  The ni56 electron capture now uses the weaklib rate rather than the old Mazurek rate.


I fixed a bug in my implementation of the Traxler et al option for thermohaline so it finally works.


We now have "hooks" for creating data for other pulsation codes (other_get_pulsation_info and other_write_pulsation_info).


I'm working with Dennis Stello to add an option in star/astero for using ratios in the chi^2.  It is still under development,
but you are welcome to give it a try.  There's even a new ratios plot much like the existing echelle plot.


I added separate control parameters to specify cache locations so that they don't need to be in the mesa/data directory.
They will still default to that location, but now we have the option to have many users share the same main mesa
source directory while having individual cache directories.  The controls are in star_job_defaults

   ! cache directories
   
      ! mesa uses caches to improve performance.
      ! the default location for these is in the mesa/data directory,
      ! but in some situations it is useful to keep the caches
      ! separately so, for example, multiple users can share the code
      ! and each can have a separate set of caches.
      ! '' means use default location for cache.
      
         eosDT_cache_dir = ''
         eosPT_cache_dir = ''
         ionization_cache_dir = ''
         kap_cache_dir = ''
         rates_cache_dir = ''
         weaklib_cache_dir = ''
         
      ! if you specify cache directories, use a separate one for each.
      ! e.g., something like this
         !eosDT_cache_dir = '/Users/bpaxton/mesa_caches/eosDT_cache'
         !eosPT_cache_dir = '/Users/bpaxton/mesa_caches/eosPT_cache'
         !ionization_cache_dir = '/Users/bpaxton/mesa_caches/ionization_cache'
         !kap_cache_dir = '/Users/bpaxton/mesa_caches/kap_cache'
         !rates_cache_dir = '/Users/bpaxton/mesa_caches/rates_cache'
         !weaklib_cache_dir = '/Users/bpaxton/mesa_caches/weaklib_cache'
      ! you much create the directories yourself -- mesa doesn't do it automatically.



Finally, if you are using ifort, you might want to change to FCopt = -O1 instead of FCopt = -O2.
I'll let Rich Townsend fill in the details on this one.


Cheers,
Bill