[mesa-users] official release: mesa version 6794 is now available

Francis Timmes fxt44 at mac.com
Sun Jul 20 22:41:00 EDT 2014

MESA version 6794 is now available.

The simplest way to get MESA, with the smallest footprint, is to 
download the ~1 GB zip file. You may, of course, continue to use svn.
see http://mesa.sourceforge.net/prereqs.html for the details.

below is an outline of the changes since the last release (6596, June 4, 2014).


Documentation - Josiah, Frank

     The files controls.defaults, star_job.defaults, and pgstar.defaults
     have been reformatted to make it easier for markup langauges (and humans!)
     to parse the structure of these files. For example, these reformatted files 
     allow for improved online documentation of each of MESA's adjustable parameters:



Mixing - Bill 

     Seperate controls for semiconvection and thermohaline mixing

          Previous versions allowed for both or neither semiconvection and thermohaline mixing
          by setting the flag "use_Ledoux_criterion" to be true or false. This single flag is
          now replaced by two flags 


          The first flag enables semiconvection and the second enables thermohaline mixing.  It is
          now possible to turn both off, one off and the other on, or both on.


Rotation - Bill, Pascale, Corentin

     Angular Momentum Viscosity 

          Corentin Cadiou found a bug in star/private/mix_info, and as a side effect of fixing it 
          there has been a redefinition of a few controls. The old controls 


          are replaced by 


          to indicate that they apply to am_nu_non_rot.

     Chemical Mixing By Rotation

          The following changes to the default angular momentm and chemical mixing by rotation
          were requested by Pascale Garaud, who will fill in details in a followup email to mesa-users.

          old defaults
               am_nu_visc_factor = -1       << this defaulted to value of D_visc_factor which was =0 by default
               am_D_mix_factor = 0.0333333333333333d0    << chem mixing by rotation was on by default
               D_DSI_factor = 1
               D_SH_factor = 1
               D_SSI_factor = 1
               D_ES_factor = 1
               D_GSF_factor = 1
               D_ST_factor = 1

          new defaults
               am_nu_visc_factor = 1        <<< viscosity is now included in angular momentum transport by default
               am_D_mix_factor = 0          <<< chem mixing by rotation is now off by default
               D_DSI_factor = 0
               D_SH_factor  = 0
               D_SSI_factor = 0
               D_ES_factor  = 0
               D_GSF_factor = 0
               D_ST_factor  = 0


Networks - Bill, Frank

     Larger nets to core-collapse

          Three new test suite cases illustrate the capability of using reaction networks
          containing a few hundred isotopes for the advanced stages of evolution in massive stars

               30M_big_net  - silicon core burn
               30M_logT_9.8_big_net  - silicon shell burning
               30M_core_collpase_big_net - final infall 

          These all use the mesa_201.net without NSE or QSE approximations.

     Approx21 nets 

          The approx21 nets now have variants that include co56 with physical electron capture rates
          from ni56 to co56 and co56 to fe56.  The conversion of fe56 to a neutron rich isotope is 
          handled the same as in the approx21 nets without co56, namely by an artificial rate of 
          electron capture that is a given factor times the ni56 electron capture rate.  The isotope 
          co56 shows up in significant amounts during the late stages just before core collapse.


Pgstar - Bill, Frank, Broxton, Dean

     Abundance profile plots

          The control name "Adundance_which_isos_to_show" 
          has changed to   "Abundance_which_isos_to_show".
          This typo correction in the control name will require you to adjust 
          the spelling in your Abundance profile plots. As an explicit example, 

               ! isotopes to plot
               Abundance_num_isos_to_show = 1
               Adundance_which_isos_to_show(1) = 'h1'

          must be changed to 

               ! isotopes to plot
               Abundance_num_isos_to_show = 1
               Abundance_which_isos_to_show(1) = 'h1'

      TRho_Profile plots
          Added a control to show the locations of the "inner" and "outer" boundaries
          used in the mass gain/loss remeshing procedure described in section 6.2 of 
          mesa I instrument paper. In addition, the location of newly accreted material 
          is also shown.
               show_TRho_accretion_mesh_borders = .false. by default
          Added a control to change the x-coordinate to mass coordinate.

               TRho_switch_to_mass = .false. by default

      Profile Panel Plots

          The underlying mass grid, or more precisely the boundaries between cells in MESA's
          finite volume scheme, on all Profile Panel plots can be shown by toggling the logical

               Profile_Panels[1-9]_show_grid = .true. / .false.

          This can be useful for visually checking there is adequate mass/spatial resolution
          in regions of interest, tracking moving fronts, and so on.

      Grid Plots 

          Grid plots are now treated like all the other kinds of plots with an 
          optional title, age, and model at top. New controls for setting the 
          size and position of the title, age, model:



               pgstar_model_fjust 1.0

          Age and model number are now only shown for the Grid plot, not for every subplots.
          New controls for adjusting the label-to-axis spacing for all subplots


          and finally new controls for titles on Grid plots



          A new control for adjusting the line width of pgstar plots


          See the star/defaults/pgstar.defaults or http://mesa.sourceforge.net/pgstar_defaults.html for details.


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