# kap module controls¶

The MESA/kap parameters are given default values here. The actual values as modified by your inlist are stored in the Kap_General_Info data structure. They can be accessed by code at runtime using the kap_handle to get a pointer to it.

## Base metallicity¶

### Zbase¶

The base metallicity for the opacity tables. This provides the reference metallicity necessary to calculate element variations. Physically, this usually corresponds to the initial metallicity of the star.

Zbase = -1


## Table selection¶

### kap_file_prefix¶

Select the set of opacity tables for higher temperature, hydrogen-rich conditions. Also referred to as Type1 tables. See Blend controls to understand precisely when these tables are used.

These tables use the value of Zbase for Z, unless use_Zbase_for_Type1 = .false..

The Type1 tables cover a wider range of X and have a higher resolution in Z for each X than Type2. The Type1 tables are for (X,Z) pairs from the following sets:

• X: 0.0, 0.1, 0.2, 0.35, 0.5, 0.7, 0.8, 0.9, 0.95, 1-Z
• Z: 0.0, 1e-4, 3e-4, 1e-3, 2e-3, 4e-3, 1e-2, 2e-2, 3e-2, 4e-2, 6e-2, 8e-1, 1e-1

Available options:

• 'gn93'
• 'gs98'
• 'a09'
• 'OP_gs98'
• 'OP_a09_nans_removed_by_hand'
kap_file_prefix = 'gs98'


### kap_CO_prefix¶

Select the set of opacity tables for higher temperature, hydrogen-poor/metal-rich conditions. Also referred to as Type2 tables. Critically, Type2 tables account for C and O enhancement during and after He burning. See Blend controls to understand precisely when these tables are used. abundances previous to any CO enhancement. Ignored if use_Type2_opacities = .false..

These tables use the value of Zbase as the base metallicity.

The Type2 tables are for (X,Z) pairs from the following sets:

• X: 0.0, 0.03, 0.10, 0.35, 0.70
• Z: 0.00, 0.001, 0.004, 0.01, 0.02, 0.03, 0.05, 0.1

Available options:

• 'gn93_co'
• 'gs98_co'
• 'a09_co'
kap_CO_prefix = 'gs98_co'


### kap_lowT_prefix¶

Select a set of opacity tables for lower temperatures.

Available options:

• 'lowT_Freedman11'
• 'lowT_fa05_gs98'
• 'lowT_fa05_gn93'
• 'lowT_fa05_a09p'
• 'lowT_af94_gn93'
• 'lowT_rt14_ag89'
• 'kapCN'
• 'AESOPUS'

kap_CN uses tables from

Lederer, M. T.; Aringer, B. (2009)
Low temperature Rosseland opacities with varied abundances of carbon and nitrogen

'AESOPUS' uses tables from AESOPUS

Marigo, P.; Aringer, B. (2009)
Low-temperature gas opacity. ÆSOPUS: a versatile and quick computational tool

Specify which file using AESOPUS_filename. The file is first looked for in the work directory. If not found, then data/kap_data is searched. Currently one set of opacities is provided, with the filename 'AESOPUS_AGSS09.h5'.

To see more detail about the composition details of the tables set show_info = .true..

You can generate your own tables with their web interface at http://stev.oapd.inaf.it/cgi-bin/aesopus . See kap/preprocessor/AESOPUS/README for information on preparing the tables for MESA.

kap_lowT_prefix = 'lowT_fa05_gs98'
AESOPUS_filename = '' ! used only if kap_lowT_prefix = 'AESOPUS'


## Blend controls¶

### use_Zbase_for_Type1¶

If true, then if use_Type2_opacities = .true., Type1 opacities will be computed using Zbase instead of Z when Z > Zbase. This helps with blending from Type1 to Type2. Ignored if use_Type2_opacities = .false..

use_Zbase_for_Type1 = .true.


### use_Type2_opacities¶

Select whether to use Type2 opacity tables (see kap_CO_prefix). Even when true, in regions where hydrogen is above a given threshold, or the metallicity is not significantly higher than Zbase, Type1 tables are used instead, with blending regions to smoothly transition from one to the other (see following controls).

use_Type2_opacities = .true.


### kap_Type2_full_on_X¶

Switch to Type1 if X too large. Type2 is full off for X >= kap_Type2_full_off_X Type2 can be full on for X <= kap_Type2_full_on_X.

kap_Type2_full_off_X = 1d-3
kap_Type2_full_on_X = 1d-6


### kap_Type2_full_on_dZ¶

Switch to Type1 if dZ too small (dZ = Z - Zbase). Type2 is full off for dZ <= kap_Type2_full_off_dZ. Type2 can be full on for dZ >= kap_Type2_full_on_dZ.

kap_Type2_full_off_dZ = 0.001d0
kap_Type2_full_on_dZ = 0.01d0


X and dZ terms are multiplied to get actual fraction of Type2. The fraction of Type2 is calculated for each cell depending on the X and dZ for that cell. So you can be using Type1 in cells where X is large or dZ is small, while at the same time you can be using Type2 where X is small and dZ is large. When frac_Type2 is > 0 and < 1, then both Type1 and Type2 are evaluated and combined linearly as (1-frac_Type2)*kap_type1 + frac_Type2*kap_type2. Add kap_frac_Type2 to your profile columns list to see frac_Type2 for each cell.

### kap_blend_logT_lower_bdy¶

Region to blend between higher temperature tables (see kap_file_prefix and kap_CO_prefix) and lower temperature tables (see kap_lowT_prefix).

The upper/lower blend boundary will be clipped to the true extent of the opacity tables. The upper boundary will be min of kap_blend_logT_upper_bdy and the max logT for lowT tables. The lower boundary will be max of kap_blend_logT_lower_bdy and min logT for highT tables. The typical min logT of the higher temperature tables tables is 3.75. Check your tables to be sure.

It is probably a good idea to keep the blend away from H ionization. logT upper of about 3.9 or a bit less will do that.

kap_blend_logT_upper_bdy = 3.88d0
kap_blend_logT_lower_bdy = 3.80d0


## Interpolation options¶

### cubic_interpolation_in_X¶

type of interpolation in X. true is cubic; false is linear.

cubic_interpolation_in_X = .false.


### cubic_interpolation_in_Z¶

type of interpolation in Z. true is cubic; false is linear.

cubic_interpolation_in_Z = .false.


## Custom tables¶

If the prefix options in Table selection above do not match one of the available options, MESA still searches for files in data/kap_data with the given prefix. This allows for custom tables. However, the user must also indicate the X and Z values for which the tables are provided.

Separate controls exist for each class of prefix.

### user_num_kap_Xs¶

Number of X values.

! user_num_kap_Xs = 10


### user_kap_Xs¶

X values for the tables (length user_num_kap_Xs). Values such that X + Z > 1 will have X reduced to 1-Z. Choose user_num_kap_Xs_for_this_Z such that at most 1 X value for each Z will be reduced in this way.

! user_kap_Xs = 0.0d0, 0.1d0, 0.2d0, 0.35d0, 0.5d0, 0.7d0, 0.8d0, 0.9d0, 0.95d0, 1.0d0


### user_num_kap_Zs¶

Number of Z values.

! user_num_kap_Zs = 13


### user_kap_Zs¶

Z values for the tables (length user_num_kap_Zs).

! user_kap_Zs = 0.000d0, 0.0001d0, 0.0003d0, 0.001d0, 0.002d0, 0.004d0, 0.01d0, 0.02d0, 0.03d0, 0.04d0, 0.06d0, 0.08d0, 0.100d0


### user_num_kap_Xs_for_this_Z¶

At different values of Z, the number of values of X may change. In particular, tables with X > 1-Z will not exist. Use the first N (<= user_num_kap_Xs) X values for the tables of the corresponding Z (length user_num_kap_Zs).

! user_num_kap_Xs_for_this_Z = 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 9, 9, 8


### user_num_kap_CO_Xs¶

Number of X values.

! user_num_kap_CO_Xs = 5


### user_kap_CO_Xs¶

X values for the tables (length user_num_kap_CO_Xs).

! user_kap_CO_Xs = 0.00d0, 0.03d0, 0.10d0, 0.35d0, 0.70d0


### user_num_kap_CO_Zs¶

Number of Z values.

! user_num_kap_CO_Zs = 8


### user_kap_CO_Zs¶

Z values for the tables (length user_num_kap_CO_Zs).

! user_kap_CO_Zs = 0.000d0, 0.001d0, 0.004d0, 0.010d0, 0.020d0, 0.030d0, 0.050d0, 0.100d0


### user_num_kap_CO_Xs_for_this_Z¶

At different values of Z, the number of values of X may change. In particular, tables with X > 1-Z will not exist. Use the first N (<= user_num_kap_CO_Xs) X values for the tables of the corresponding Z (length user_num_kap_CO_Zs).

! user_num_kap_CO_Xs_for_this_Z = 5, 5, 5, 5, 5, 5, 5, 5


### user_num_kap_lowT_Xs¶

Number of X values.

! user_num_kap_lowT_Xs = 10


### user_kap_lowT_Xs¶

X values for the tables (length user_num_kap_lowT_Xs). Values such that X + Z > 1 will have X reduced to 1-Z. Choose user_num_kap_lowT_Xs_for_this_Z such that at most 1 X value for each Z will be reduced in this way.

! user_kap_lowT_Xs = 0.0d0, 0.1d0, 0.2d0, 0.35d0, 0.5d0, 0.7d0, 0.8d0, 0.9d0, 0.95d0, 1.0d0


### user_num_kap_lowT_Zs¶

Number of Z values.

! user_num_kap_lowT_Zs = 13


### user_kap_lowT_Zs¶

Z values for the tables (length user_num_kap_lowT_Zs).

! user_kap_lowT_Zs = 0.000d0, 0.0001d0, 0.0003d0, 0.001d0, 0.002d0, 0.004d0, 0.01d0, 0.02d0, 0.03d0, 0.04d0, 0.06d0, 0.08d0, 0.100d0


### user_num_kap_lowT_Xs_for_this_Z¶

At different values of Z, the number of values of X may change. In particular, tables with X > 1-Z will not exist. Use the first N (<= user_num_kap_lowT_Xs) X values for the tables of the corresponding Z (length user_num_kap_lowT_Zs).

! user_num_kap_lowT_Xs_for_this_Z = 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 9, 9, 8


## Conductive opacity options¶

### include_electron_conduction¶

include_electron_conduction = .true.


### use_blouin_conductive_opacities¶

Use fits from Blouin et al. (2020) for H and He in the regime of moderate coupling and moderate degeneracy.

use_blouin_conductive_opacities = .true.


## Miscellaneous controls¶

### show_info¶

if true, then output additional information as the opacities are loaded. this is particularly useful to see the detailed composition coverage of the AESOPUS opacity files.

show_info = .false.


## Other hooks¶

Control whether to use other hooks. See kap/other.

### use_other_elect_cond_opacity¶

Replace electron conduction opacity routine

use_other_elect_cond_opacity = .false.


### use_other_compton_opacity¶

Replace Compton opacity routine

use_other_compton_opacity = .false.


Replace radiative opacity routine. The standard routine evaluates the opacity using the low-T and high-T tables.

use_other_radiative_opacity = .false.


## Debugging controls¶

Specify a range of calls for which to receive debugging information.

dbg = .false.
logT_lo = -1d99
logT_hi = 1d99
logRho_lo = -1d99
logRho_hi = 1d99
X_lo = -1d99
X_hi = 1d99
Z_lo = -1d99
Z_hi = 1d99