[mesa-users] Opacity Type I in the envelope and Type II in the core

[Ehsan Moravveji]

Dear mesa users,
As you know, the OP Type I tables are limited to logT<=8.0, whereas OPAL Type I and CO-enhanced Type II extend to logT<=8.7; therefore, it one can only use the OPAL tables for after core He burning anyway.

I would like to blend the two sets of opacity tables, so that after the TAMS, the OP Type I tables are used in the envelope, and the OPAL Type II tables are used near the core, anywhere temperature drops below say logT<7.60.
I only wanted to double check with you if the following star_job and controls settings do this for me. They are trimmed from the full inlist:

&star_job
      kappa_type2_logT_lower_bdy = 7.60d0
/

&controls
    cubic_interpolation_in_Z = .true.
    use_Type2_opacities = .true.
    Zbase = 0.02
    kap_Type2_full_off_X = 1d-6
    kap_Type2_full_on_X = 1d-6
/

Moreover, in controls.defaults, there is a mention of possibly blending Type I and Type II tables giving the blend weight “frac_Type2”, but this variable is not made publicly available in the controls inlist.
For my purpose, do I also need to use frac_Type2?

Best regards
Ehsan.