! ===============
! binary_controls
! ===============

! specifications for starting model
! =================================


! m1
! ~~

! Initial mass of star 1 in Msun units. Not used when loading a saved model.
! same caveats as ``initial_mass`` in star/defaults/controls.defaults apply

! ::

   m1 = 1.0d0


! m2
! ~~

! Initial mass of star 2 in Msun units. Not used when loading a saved model.
! same caveats as ``initial_mass`` in star/defaults/controls.defaults apply

! ::

   m2 = 0.8d0


! initial_period_in_days
! ~~~~~~~~~~~~~~~~~~~~~~

! Initial orbital period in days.

! ::

   initial_period_in_days = 0.5d0


! initial_separation_in_Rsuns
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Initial separation measured in Rsuns. Only used when ``initial_period_in_days < 0``

! ::

   initial_separation_in_Rsuns = 100


! initial_eccentricity

! Initial eccentricity of the system
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! ::

   initial_eccentricity = 0.0d0


! controls for output
! ===================


! history_name
! ~~~~~~~~~~~~

! Name of file for binary output

! ::

   history_name = 'binary_history.data'


! history_interval
! ~~~~~~~~~~~~~~~~

! append an entry to the history.data file when
! ``mod(model_number, history_interval) = 0``.

! ::

   history_interval = 5


! append_to_star_history
! ~~~~~~~~~~~~~~~~~~~~~~

! If true, then the columns from the ``binary_history`` are also included
! in each of the stars history files.
! NOTE: if .false., then pgstar cannot access binary data

! ::

   append_to_star_history = .true.


! log_directory
! ~~~~~~~~~~~~~

! Directory for binary output

! ::

   log_directory = '.'


! history_dbl_format
! ~~~~~~~~~~~~~~~~~~
! history_int_format
! ~~~~~~~~~~~~~~~~~~
! history_txt_format
! ~~~~~~~~~~~~~~~~~~

! Format for double, int and text in binary output

! ::

   history_dbl_format = '(1pes32.16e3, 1x)'
   history_int_format = '(i32, 1x)'
   history_txt_format = '(a32, 1x)'


! photo_interval
! ~~~~~~~~~~~~~~
! photo_digits
! ~~~~~~~~~~~~
! photo_directory
! ~~~~~~~~~~~~~~~

! These overwrite the values of ``photo_interval``, ``photo_digits`` and ``photo_directory`` for each
! star, so that profiles are outputted simultaneously

! ::

   photo_interval = 50
   photo_digits = 3
   photo_directory = 'photos'


! terminal_interval
! ~~~~~~~~~~~~~~~~~

! write info to terminal when ``mod(model_number, terminal_interval) = 0``.

! ::

   terminal_interval = 1


! write_header_frequency
! ~~~~~~~~~~~~~~~~~~~~~~

! output the log header info to the terminal when
! ``mod(model_number, write_header_frequency*terminal_interval) = 0``.

! ::

   write_header_frequency = 10


! extra_binary_terminal_output_file
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! if not empty, output terminal info to this file in addition to terminal.
! this does not capture all of the terminal output -- just the common items.
! it is intended for use in situations where you cannot directly see the terminal
! output such as when running on a cluster. if you want to be able to monitor
! the progress for such cases, you can set ``extra_binary_terminal_output_file = 'log'``
! and then do tail -f log to view the terminal output as it is recorded in the file.

! ::

   extra_binary_terminal_output_file = ''

! timestep controls
! =================

! The terminal output during evolution includes a short string for the 'dt_limit'.
! This is to give you some indication of what is limiting the time steps.
! Here's a dictionary mapping those terminal strings to the corresponding control parameters.
! These only include limits from binary, to see the limits from star refer to
! star/default/controls.defaults

! ::

!           terminal output       related parameter
!          'b_companion'          timestep limited by companion
!          'b_RL'                 fr
!          'b_jorb'               fj
!          'b_envelope'           fm
!          'b_separation'         fa
!          'b_eccentricity'       fe
!          'b_deltam'             fdm


! time_delta_coeff
! ~~~~~~~~~~~~~~~~
! similarly to star/time_delta_coeff, this time_delta_coeff can be scaled to force smaller timestep for binary timestep
! controls
! ::

   time_delta_coeff = 1d0


! fm
! ~~
! fm_hard
! ~~~~~~~
! fa
! ~~
! fa_hard
! ~~~~~~~
! fr
! ~~
! fr_hard
! ~~~~~~~
! fj
! ~~
! fj_hard
! ~~~~~~~
! fe
! ~~
! fe_hard
! ~~~~~~~

! Timestep controls based on relative changes. After each step
! an upper limit is set on the timestep based on changes on different
! quantities. If the quantity is X and the change in one timestep dX,
! then this limit is given by

! ::

!     dt_next_max = dt * fX*abs(X / dX)

! each of these controls deals with the following:

! + fm: envelope mass
! + fa: binary separation
! + fr: change in (r-rl)/rl
! + fj: change in orbital angular momentum
! + fe: change in orbital eccentricity

! hard limits are strictly enforced, if a timestep exceeds that limit
! then a retry is made.

! ::

   fm = 0.01d0
   fm_hard = -1d0
   fa = 0.01d0
   fa_hard = 0.02d0
   fr = 0.10d0
   fr_hard = -1d0
   fj = 0.001d0
   fj_hard = 0.01d0
   fe = 0.01d0
   fe_hard = -1d0


! fm_limit
! ~~~~~~~~
! fr_limit
! ~~~~~~~~
! fe_limit
! ~~~~~~~~

! Limits to timestep controls give by fm, fr and fe.
! As these three quantities evolve naturally to zero,
! following strictly the timestep limit given by fX would
! reduce timesteps indefinitely. These fX_limit avoid this problem
! by computing the limit to the timestep as

! ::

!     dt_next_max = dt * fX*abs(max(abs(X),fX_limit) / dX)

! If any of these ``fX_limit`` is smaller than zero it is ignored.

! ::

   fm_limit = 1d-3
   fr_limit = 1d-2
   fe_limit = 1d-1


! fr_dt_limit
! ~~~~~~~~~~~

! Minimum timestep limit allowed for the fr control in years.

! ::

   fr_dt_limit = 10d0


! fdm
! ~~~


! fdm_hard
! ~~~~~~~~

! Limits the timestep based on the fractional mass change of either component.

! ::

   fdm = 0.005d0
   fdm_hard = 0.01d0


! dt_softening_factor
! ~~~~~~~~~~~~~~~~~~~

! Weight factor to average ``max_timestep`` with old one (in log space) as in

! ::

!     dt_next_max = 10**(dt_softening_factor*log10(dt_next_max_old) + &
!         (1-dt_softening_factor)*log10(dt_next_max))

! where ``dt_next_max_old`` is the limit used in the previous step. This is meant
! to avoid large changes in dt. Values must be < 1 and >= 0, 1 meaning constant dt,
! 0 meaning no softening

! ::

   dt_softening_factor = 0.5d0


! varcontrol_{stage}
! ~~~~~~~~~~~~~~~~~~

! Allows binary to set ``varcontrol_target`` for each star depending on the
! stage of evolution. Ignored if < 0. Each one controls the following stages,

! + ``varcontrol_case_a`` : ``varcontrol_target`` for both stars during mass transfer
!                     from a core hydrogen burning star.
! + ``varcontrol_case_b`` : ``varcontrol_target`` for both stars during mass transfer
!                     from a core hydrogen depleted star.
! + ``varcontrol_ms`` : ``varcontrol_target`` for a star that has not depleted core H.
! + ``varcontrol_post_ms`` : ``varcontrol_target`` for a star that has depleted core H.

! ::

   varcontrol_case_a = -1d0
   varcontrol_case_b = -1d0
   varcontrol_ms = -1d0
   varcontrol_post_ms = -1d0


! dt_reduction_factor_for_j
! ~~~~~~~~~~~~~~~~~~~~~~~~~

! When a retry happens due to the hard limit in angular momentum changes, or
! because the timestep produced a negative j, further multiply the timestep by this factor for
! the next step. This can avoid multiple retries and waste of time.

! ::

   dt_reduction_factor_for_j = 0.1d0

! when to stop
! ============


! accretor_overflow_terminate
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! terminate evolution if (r-rl)/rl is bigger than this for accretor

! ::

   accretor_overflow_terminate = 0.0d0


! terminate_if_initial_overflow
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! terminate evolution if first model of run is overflowing

! ::

   terminate_if_initial_overflow = .true.


! terminate_if_L2_overflow
! ~~~~~~~~~~~~~~~~~~~~~~~~

! terminate evolution if there is overflow through the second Lagrangian point
! Amount of overflow needed to reach L2 implemented as in Marchant et al. (2016), A&A, 588, A50

! ::

   terminate_if_L2_overflow = .false.


! mass transfer controls
! ======================


! mass_transfer_*
! ~~~~~~~~~~~~~~~

! Transfer efficiency controls.
! alpha, beta, delta and gamma parameters as described in Tauris & van den Heuvel 2006
! section 16.4.1, transfer efficiency is given by 1-alpha-beta-delta.

! These only affect mass that is lost from the donor due to mass transfer, winds from each
! star will carry away angular momentum from the vicinity of each even when transfer efficiency
! is unity. Each of these represent the following:

! + alpha : fraction of mass lost from the vicinity of the donor as fast wind
! + beta : fraction of mass lost from the vicinity of the accretor as fast wind
! + delta : fraction of mass lost from circumbinary coplanar toroid
! + gamma : radius of the circumbinary coplanar toroid is ``gamma**2 * orbital_separation``

! ::

   mass_transfer_alpha = 0.0d0
   mass_transfer_beta = 0.0d0
   mass_transfer_delta = 0.0d0
   mass_transfer_gamma = 0.0d0


! limit_retention_by_mdot_edd
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Limit accretion using ``mdot_edd``. The current implementation is intended for use with
! black hole accretors, as in, e.g., `Podsiadlowski, Rappaport & Han (2003) <https://ui.adsabs.harvard.edu/abs/2003MNRAS.341..385P/abstract>`_.
! For other accretors ``mdot_edd`` should be set with ``use_this_for_mdot_edd``, the hook
! ``use_other_mdot_edd``, or by appropriately setting ``use_this_for_mdot_edd_eta``.
! Note: MESA versions equal or lower than 8118 used eta=1 and did not correct
! the accreted mass for the energy lost by radiation.

! If accreted material radiates an amount of energy equal to ``L=eta*mtransfer_rate*clight**2``,
! then accretion is assumed to be limited to the Eddington luminosity,

! ::

!     Ledd = 4*pi*cgrav*Mbh*clight/kappa

! which results in the Eddington mass-accretion rate

! ::

!     mdot_edd = 4*pi*cgrav*Mbh/(kappa*clight*eta)

! the efficiency eta is determined by the properties of the last stable circular orbit,
! and for a BH with no initial spin it can be expressed in terms of the initial BH mass Mbh0
! and the current BH mass,

! ::

!     eta = 1-sqrt(1-(Mbh/(3*Mbh0))**2)

! for Mbh < sqrt(6) Mbh0. For BHs with initial spins different from zero, an effective
! Mbh0 can be computed, corresponding to the mass the black hole would have needed to
! have with zero spin to reach the current mass and spin.

! ::

   limit_retention_by_mdot_edd = .false.


! use_es_opacity_for_mdot_edd
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! If .true., then the opacity for ``mdot_edd`` is computed as 0.2*(1+X)
! If .false., the opacity of the outermost cell of the donor is used

! ::

   use_es_opacity_for_mdot_edd = .true.


! use_this_for_mdot_edd_eta
! ~~~~~~~~~~~~~~~~~~~~~~~~~

! Fixed ``mdot_edd_eta``, if negative, eta will be computed consistently as material is accreted.
! Values should be between ~0.06-0.42, the minimum corresponding to a BH with spin parameter a=0, and the maximum to a=1.

! ::

   use_this_for_mdot_edd_eta = -1


! use_radiation_corrected_transfer_rate
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! If true, then reduce the increase in mass of the BH to account for the radiated energy ``eta*mtransfer_rate_clight**2``
! so that in a timestep

! ::

!     delta_Mbh = (1-eta)*mass_transfer_rate*dt

! ::

   use_radiation_corrected_transfer_rate = .false.


! initial_bh_spin
! ~~~~~~~~~~~~~~~

! Initial spin parameter of the black hole "a". Must be between 0 and 1.
! Evolution of BH spin is done with eq. (6) of King & Kolb (1999), MNRAS, 305, 654

! ::

   initial_bh_spin = 0


! use_this_for_mdot_edd
! ~~~~~~~~~~~~~~~~~~~~~

! Fixed ``mdot_edd`` in Msun/yr, ignored if negative

! ::

   use_this_for_mdot_edd = -1


! mdot_scheme
! ~~~~~~~~~~~

! How to compute mass transfer. Options are:

! + "Ritter" : Ritter 1988, A&A, 202, 93
! + "Kolb" : Optically thick overflow of Kolb & Ritter 1990, A&A, 236, 385
! + "roche_lobe" : Set mass transfer rate such that the donor remains inside
!                its Roche lobe. Only works implicitly.
! + "contact" : Extends the roche_lobe scheme to include contact systems as in
!               Marchant et al. (2016), A&A, 588, A50

! ::

   mdot_scheme = 'Ritter'


! explicit mass transfer computation.
! ___________________________________

! MESA can compute mass transfer rates either explicitly (at the beginning
! of the step) or implicitly (iterating the solution until the mass transfer
! rate matches the value computed at the end of the step). The explicit method
! is used if ``max_tries_to_achieve <= 0``.


! cur_mdot_frac
! ~~~~~~~~~~~~~

! Average the explicit mass transfer rate computed with the old in order
! to smooth large changes.

! ::

!     mass_transfer = mass_transfer_old * cur_mdot_frac + (1-cur_mdot_frac) * mass_transfer

! ::

   cur_mdot_frac = 0.5d0


! max_explicit_abs_mdot
! ~~~~~~~~~~~~~~~~~~~~~

! Limit the explicit mass transfer rate to ``max_explicit_abs_mdot``, in Msun/secyer

! ::

   max_explicit_abs_mdot = 1d-7


! implicit mass transfer computation.
! ___________________________________


! max_tries_to_achieve
! ~~~~~~~~~~~~~~~~~~~~

! The implicit method will modify the mass transfer rate and redo the step until
! it either finds a solution, or the number of tries goes above ``max_tries_to_achieve``.
! if ``max_tries_to_achieve <= 0`` the explicit method is used.

! ::

   max_tries_to_achieve = 20


! solver_type
! ~~~~~~~~~~~

! Method use to solve for mass transfer. The solver first attempts to increase or
! reduce the mass transfer rate used through the step until finding an upper and
! lower limit to it. This controls what is done after that point. Options are:

! + "cubic" : Given an upper and lower limit, plus a new try in between,
!             the root of the equation is estimated by using a cubic matching the
!             three points.
! + "bisect" : Simply takes the average of the boundaries for the next try
! + "both" : Alternates between cubic and bisect each iteration

! ::

   solver_type = 'both'


! implicit_scheme_tolerance
! ~~~~~~~~~~~~~~~~~~~~~~~~~

! Tolerance for which a solution is considered valid. For the Ritter and Kolb
! schemes if we call mdot the mass transfer rate used for the step, and mdot_end
! the one computed at the end of it, a solution is valid if ::

!     abs((mdot-mdot_end)/mdot_end) < b% implicit_scheme_tolerance

! For the roche_lobe scheme, a solution will be considered valid if

!     -implicit_scheme_tolerance < (r-rl)/rl < 0

! When using the roche_lobe scheme smaller values of order 1d-3 or smaller are
! recommended.

! ::

   implicit_scheme_tolerance = 1d-2


! implicit_scheme_tiny_factor
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! During the implicit scheme the solution is bracketed between a minimum and a
! maximum value mdot_hi and mdot_lo. Even if the desired tolerance is not achieved,
! the solution is accepted if the difference between abs(mdot_hi-mdot_lo) is smaller
! than implicit_scheme_tiny_factor*min(abs(mdot_hi),abs(mdot_lo))

! ::

   implicit_scheme_tiny_factor = 1d-6


! initial_change_factor
! ~~~~~~~~~~~~~~~~~~~~~


! change_factor_fraction
! ~~~~~~~~~~~~~~~~~~~~~~


! implicit_lambda
! ~~~~~~~~~~~~~~~

! The implicit scheme works by adjusting the mass transfer rate from the previous
! step until it finds a solution. If the mass transfer needs to increase/reduce after
! a try, then it is multiplied/divided by ``change_factor``. ``initial_change_factor`` provides
! the initial value for this parameter, however, since at certain points the mass
! transfer rate will increase steeply and at others remain mostly constant from step
! to step, MESA adjusts the value of the change factor to make it easier to find
! solutions. Whenever the mass transfer rate changes from the previous value, MESA
! will modify the ``change_factor`` according to:

! ::

!     if(mass_transfer_rate < mass_transfer_prev) then
!        change_factor = change_factor*(1.0-implicit_lambda) &
!           + implicit_lambda*(1+change_factor_fraction*(mass_transfer_rate/mass_transfer_prev-1))
!     else
!        change_factor = change_factor*(1.0-implicit_lambda) &
!           + implicit_lambda*(1+change_factor_fraction*(mass_transfer_prev/mass_transfer_rate-1))
!     end if

! Choosing ``implicit_lambda = 0`` will keep the change factor constant.

! ::

   initial_change_factor = 1.5d0
   change_factor_fraction = 0.9d0
   implicit_lambda = 0.25d0


! max_change_factor
! ~~~~~~~~~~~~~~~~~


! min_change_factor
! ~~~~~~~~~~~~~~~~~

! Maximum and minimum values for the ``change_factor``

! ::

   max_change_factor = 1.5d0
   min_change_factor = 1.05d0


! num_tries_for_increase_change_factor
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


! change_factor_increase
! ~~~~~~~~~~~~~~~~~~~~~~

! If after every ``num_tries_for_increase_change_factor`` iterations the implicit scheme does not have upper
! and lower bounds for the mass transfer rate, multiply ``change_factor`` by ``change_factor_increase``. Ignored if
! ``num_tries_for_increase_change_factor < 1``. Increase is limited to ``max_change_factor``.

! ::

   num_tries_for_increase_change_factor = 20
   change_factor_increase = 1.1d0


! starting_mdot
! ~~~~~~~~~~~~~

! When using the ``roche_lobe`` scheme, if the donor overflows for the first time
! use ``starting_mdot`` (in Msun/secyer) as an initial guess for the mass transfer rate.

! ::

   starting_mdot = 1d-12


! roche_min_mdot
! ~~~~~~~~~~~~~~

! When using the ``roche_lobe`` scheme, if mass transfer rate is below ``roche_min_mdot``
! (in Msun/secyer) and the donor is not overflowing its roche lobe, assume detachment
! and stop mass transfer.

! ::

   roche_min_mdot = 1d-16


! min_mdot_for_implicit
! ~~~~~~~~~~~~~~~~~~~~~

! For any choice except for the ``roche_lobe`` scheme mass transfer will be computed explicitly
! until the explicit computation of mdot is > ``min_mdot_for_implicit`` (in Msun/secyer),
! even if ``max_tries_to_achieve`` > 0. This is to avoid spending many iterations when the stars
! are detached and the explicit calculation gives very low values of mdot.

! ::

   min_mdot_for_implicit = 1d-16


! max_implicit_abs_mdot
! ~~~~~~~~~~~~~~~~~~~~~

! Limit the implicit mass transfer rate to ``max_implicit_abs_mdot``, in Msun/secyer

! ::

   max_implicit_abs_mdot = 1d99


! report_rlo_solver_progress
! ~~~~~~~~~~~~~~~~~~~~~~~~~~

! Set true to see info about the iterations to compute mass transfer from RLOF

! ::

   report_rlo_solver_progress = .false.


! Tidal wind enhancement
! ______________________


! do_enhance_wind_*
! ~~~~~~~~~~~~~~~~~

! Use the Tout & Eggleton mechanism to tidally enhance the wind mass
! loss from one or both components according to:

!     Mdot_w = Mdot_w * ( 1 + B_wind * min( (R/RL)^6, 0.5^6 ) )

! Tout & Eggleton 1988,MNRAS,231,823 (eq. 2)

! "\_1" refers to first star, "\_2" to the second one.

! ::

   do_enhance_wind_1 = .false.
   do_enhance_wind_2 = .false.


! tout_B_wind_*
! ~~~~~~~~~~~~~

! The ``B_wind`` parameter from the previous equation. Default value is
! taken from Tout & Eggleton 1988,MNRAS,231,823

! "\_1" refers to first star, "\_2" to the second one.

! ::

   tout_B_wind_1 = 1d4
   tout_B_wind_2 = 1d4


! Wind mass accretion
! ___________________


! do_wind_mass_transfer_*
! ~~~~~~~~~~~~~~~~~~~~~~~

! transfer part of the mass lost due to stellar winds from the mass losing
! component to its companion. Using the Bondi-Hoyle mechanism.
! "\_1" refers to first star, "\_2" to the second one.

! ::

   do_wind_mass_transfer_1 = .false.
   do_wind_mass_transfer_2 = .false.


! wind_BH_alpha_*
! ~~~~~~~~~~~~~~~

! Bondi-Hoyle accretion parameter for each star. The default for alpha is 3/2
! taken from Hurley et al. 2002, MNRAS, 329, 897, in agreement with
! Boffin & Jorissen 1988, A&A, 205, 155.
! The default for beta is 1/8=0.125 in accordance for results of cool
! supergiants from Kucinskas A., 1999, Ap&SS, 262, 127
! "\_1" refers to first star, "\_2" to the second one.

! ::

   wind_BH_alpha_1 = 1.5d0
   wind_BH_alpha_2 = 1.5d0
   wind_BH_beta_1 = 1.25d-1
   wind_BH_beta_2 = 1.25d-1


! max_wind_transfer_fraction_*
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Upper limit on the wind transfer fraction for star *
! "\_1" refers to first star, "\_2" to the second one.

! ::

   max_wind_transfer_fraction_1 = 0.5d0
   max_wind_transfer_fraction_2 = 0.5d0

! orbital jdot controls
! =====================


! do_jdot_gr
! ~~~~~~~~~~

! Include gravitational wave radiation in jdot

! ::

   do_jdot_gr = .true.


! do_jdot_ml
! ~~~~~~~~~~

! Include loss of angular momentum via mass loss. The parameters
! ``mass_transfer_*`` determine the fractions of mass lost from the vicinity
! of the donor, the accretor, or a circumbinary coplanar toroid.

! ::

   do_jdot_ml = .true.


! do_jdot_ls
! ~~~~~~~~~~

! Fix jdot such that the total angular momentum of the system is conserved,
! except for loses due to other jdot mechanisms, or angular momentum loss
! from winds. This is meant to take care of L-S coupling due to tides.

! ::

   do_jdot_ls = .true.


! do_jdot_missing_wind
! ~~~~~~~~~~~~~~~~~~~~

! Usually MESA computes stellar AM loss due to winds by taking the angular momentum from
! the removed layers of the star. However, when mass transfer is included, wind mass
! loss and mass accretion are added up, and only the remainder, if corresponding to
! net mass loss, contributes to stellar AM loss. ``jdot_missing_wind`` compensates for this,
! by removing from the orbit an amount of angular momentum equal to the mass lost
! that does not contribute to stellar AM loss, times the specific angular momentum
! at the surface.

! ::

   do_jdot_missing_wind = .false.


! do_jdot_mb
! ~~~~~~~~~~

! Include magnetic braking as in `Rappaport, Verbunt & Joss (1983) <https://ui.adsabs.harvard.edu/abs/1983ApJ...275..713R/abstract>`_.

! ::

   do_jdot_mb = .true.


! include_accretor_mb
! ~~~~~~~~~~~~~~~~~~~

! If true, the contribution to jdot from magnetic braking of the accretor is
! also taken into account.

! ::

   include_accretor_mb = .false.


! magnetic_braking_gamma
! ~~~~~~~~~~~~~~~~~~~~~~

! gamma exponent for magnetic braking.

! ::

   magnetic_braking_gamma = 3.0d0


! keep_mb_on
! ~~~~~~~~~~

! If true keep magnetic braking even when radiative core goes away.

! ::

   keep_mb_on = .false.


! jdot_mb_min_qconv_env
! ~~~~~~~~~~~~~~~~~~~~~
! jdot_mb_max_qconv_env
! ~~~~~~~~~~~~~~~~~~~~~
! jdot_mb_max_qconv_core
! ~~~~~~~~~~~~~~~~~~~~~~
! jdot_mb_qlim_for_check_rad_core
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
! jdot_mb_qlim_for_check_conv_env
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Conditions for magnetic braking to operate. Magnetic braking is
! turned off if any of these do not apply.
! The mass fraction of the convective envelope has to be > jdot_mb_min_qconv_env.
! The mass fraction of the convective envelope has to be < jdot_mb_max_qconv_env.
! The mass fraction of the convective core has to be < jdot_mb_max_qconv_core.
! Here by mass fraction we refer to the mass of the respective zone divided by the
! total mass of the star. To compute the mass in the envelope we add all convective
! layers down to jdot_mb_qlim_for_check_conv_env, and keep adding layers downwards
! until we reach a non-convective zone. This is because the very outermost cell is
! likely radiative. A similar thing is done for the core with jdot_mb_qlim_for_check_rad_core.
! For full details check binary_jdot.f90.

! ::

   jdot_mb_min_qconv_env = 1d-6
   jdot_mb_max_qconv_env = 0.99d0
   jdot_mb_max_qconv_core = 1d-2
   jdot_mb_qlim_for_check_rad_core = 1d-3
   jdot_mb_qlim_for_check_conv_env = 0.999d0


! jdot_mb_scale_for_low_qconv_env
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
! jdot_mb_mass_frac_for_scale
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! If jdot_mb_scale_for_low_qconv_env is .true., scale down jdot_mb if mass fraction of
! the convective envelope is below jdot_mb_mass_frac_for_scale.
! (Podsiadlowski et al. 2002, The Astrophysical Journal, Volume 565, Issue 2, pp. 1107-1133)

! ::

   jdot_mb_scale_for_low_qconv_env = .true.
   jdot_mb_mass_frac_for_scale = 0.02d0


! jdot_multiplier
! ~~~~~~~~~~~~~~~

! Multiply total jdot by this factor.
! NOTE: ``jdot_ls`` is not affected by this.

! ::

   jdot_multiplier = 1d0

! rotation and sync controls
! ==========================


! do_j_accretion
! ~~~~~~~~~~~~~~

! If true, compute accretion of angular momentum following A.3.3 of
! `de Mink et al. (2013) <https://ui.adsabs.harvard.edu/abs/2013ApJ...764..166D/abstract>`_. Otherwise, incoming material is
! assumed to have the specific angular momentum of the surface of the accretor.

! ::

   do_j_accretion = .false.


! do_tidal_sync
! ~~~~~~~~~~~~~

! If true, apply tidal torque to the star

! ::

   do_tidal_sync = .false.


! sync_type_*
! ~~~~~~~~~~~

! Timescale for orbital synchronisation.
! "\_1" refers to first star, "\_2" to the second one.
! Options are:

! + "Instantaneous" : Keep the star synced to the orbit.
! + "Orb_period" : Sync in the timescale of the orbital period.
! + "Hut_conv" : Sync timescale following Hurley et al. 2002, MNRAS, 329, 897
!              for convective envelopes.
! + "Hut_rad" : Sync timescale following Hurley et al. 2002, MNRAS, 329, 897
!              for radiative envelopes.
! + "None" : No sync for this star.

! ::

   sync_type_1 = 'Hut_conv'
   sync_type_2 = 'Hut_conv'


! sync_mode_*
! ~~~~~~~~~~~

! Where angular momentum is deposited for synchronization.
! "\_1" refers to first star, "\_2" to the second one.
! Options are:

! + "Uniform" : Each layer is synced independently given the sync timescale.

! ::

   sync_mode_1 = 'Uniform'
   sync_mode_2 = 'Uniform'


! Ftid_*
! ~~~~~~

! Tidal strength factor. Synchronisation and circularisation timescales are divided by this.
! "\_1" refers to first star, "\_2" to the second one.

! ::

   Ftid_1 = 1d0
   Ftid_2 = 1d0


! do_initial_orbit_sync_*
! ~~~~~~~~~~~~~~~~~~~~~~~

! Relax rotation of star to orbital period at the beginning of evolution.
! "\_1" refers to first star, "\_2" to the second one.

! ::

   do_initial_orbit_sync_1 = .false.
   do_initial_orbit_sync_2 = .false.


! tidal_reduction
! ~~~~~~~~~~~~~~~

! ``tidal_reduction`` accounts for the reduction in the effectiveness of convective
! damping of the equilibrium tide when the tidal forcing period is less than the
! convective turnover period of the largest eddies. It corresponds to the exponent
! in eq. (32) of Hurley et al. 2002, MNRAS, 329, 897

! ``tidal_reduction`` = 1 follows Zahn(1966, 1989), while ``tidal_reduction`` = 2 follows
! Goldreich & Nicholson (1977).

! ::

   tidal_reduction = 2.0d0

! eccentricity controls
! =====================


! do_tidal_circ
! ~~~~~~~~~~~~~

! If true, apply tidal circularisation

! ::

   do_tidal_circ = .false.


! circ_type_*
! ~~~~~~~~~~~

! Mechanism for circularisation. Options are:
! "\_1" refers to first star, "\_2" to the second one.

! + "Hut_conv" : Circ timescale following Hurley et al. 2002, MNRAS, 329, 897
!              for convective envelopes.
! + "Hut_rad" : Circ timescale following Hurley et al. 2002, MNRAS, 329, 897
!              for radiative envelopes.
! + "None" : no tidal circularisation

! ::

   circ_type_1 = 'Hut_conv'
   circ_type_2 = 'Hut_conv'


! use_eccentricity_enhancement
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Flag to turn on Soker eccentricity enhancement

! ::

   use_eccentricity_enhancement = .false.


! max_abs_edot_tidal
! ~~~~~~~~~~~~~~~~~~

! Maximum absolute value for tidal edot (in 1/s). If the computed tidal edot goes
! above this, then it is fixed at this maximum

! ::

   max_abs_edot_tidal = 1d-6


! max_abs_edot_enhance
! ~~~~~~~~~~~~~~~~~~~~

! Maximum absolute value for eccentricity enhancement (in 1/s). If the computed edot goes
! above this, then it is fixed at this maximum

! ::

   max_abs_edot_enhance = 1d-6


! min_eccentricity
! ~~~~~~~~~~~~~~~~

! If after a step ``eccentricity < min_eccentricity``, then fix it at this value

! ::

   min_eccentricity = 0.0d0


! max_eccentricity
! ~~~~~~~~~~~~~~~~

! If after a step ``eccentricity > max_eccentricity``, then fix it at this value

! ::

   max_eccentricity = 0.99d0


! anomaly_steps
! ~~~~~~~~~~~~~

! For phase dependent processes, the orbit is divided into this number of steps
! in the true anomaly, to integrate through a full orbit and obtain the secular
! changes

! ::

   anomaly_steps = 500

! irradiation controls
! ====================


! accretion_powered_irradiation
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Flag to turn on irradiation of the donor due to accretion onto a compact object.

! ::

   accretion_powered_irradiation = .false.


! col_depth_for_eps_extra
! ~~~~~~~~~~~~~~~~~~~~~~~

! Energy from irradiation will be deposited in the outer
! ``4*Pi*R^2*col_depth_for_eps_extra`` grams of the star.

! ::

   col_depth_for_eps_extra = -1


! use_accretor_luminosity_for_irrad
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Flag to turn on irradiation based on the luminosity of the accretor and binary
! separation. Requires ``evolve_both_stars = .true.`` in binary_job inlist.

! ::

   use_accretor_luminosity_for_irrad = .false.


! irrad_flux_at_std_distance
! ~~~~~~~~~~~~~~~~~~~~~~~~~~


! std_distance_for_irradiation
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! If ``irrad_flux_at_std_distance > 0`` then irradiation flux is computed as

! ::

!     s% irradiation_flux = b% irrad_flux_at_std_distance * &
!         (b% std_distance_for_irradiation/b% separation)**2

! ::

   irrad_flux_at_std_distance = -1
   std_distance_for_irradiation = -1


! max_F_irr
! ~~~~~~~~~

! Limit irradiation by this amount.

! ::

   max_F_irr = 5d12

! common envelope controls (EXPERIMENTAL, DON'T USE)
! ==================================================


! CE_alpha
! ~~~~~~~~

! Common envelope efficiency factor

! ::

   CE_alpha = 1d0


! CE_alpha_th
! ~~~~~~~~~~~

! Common envelope thermal efficiency factor

! ::

   CE_alpha_th = 1d0


! CE_alpha_core
! ~~~~~~~~~~~~~

! Efficiency at which the change of energy in the core of the star contributes
! to envelope ejection.

! ::

   CE_alpha_core = 0d0


! CE_mass_loss_rate_high
! ~~~~~~~~~~~~~~~~~~~~~~

! Upper mass loss rate imposed during CE in Msun/yr

! ::

   CE_mass_loss_rate_high = 1d-1


! CE_mass_loss_rate_low
! ~~~~~~~~~~~~~~~~~~~~~

! Lower mass loss rate imposed during CE in Msun/yr

! ::

   CE_mass_loss_rate_low = 1d-6


! CE_rel_rlo_for_detachment
! ~~~~~~~~~~~~~~~~~~~~~~~~~

! Consider the CE phase terminated when (r-rl)/rl < -CE_rel_rlo_for_detachment
! Between (r-rl)/rl = 0d0 and (r-rl)/rl = -CE_rel_rlo_for_detachment the mass loss rate is
! adjusted between CE_mass_loss_rate_high and CE_mass_loss_rate_low.

! ::

   CE_rel_rlo_for_detachment = 0.02d0


! CE_years_detached_to_terminate
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! During CE, if the star spends this amount of time detached, terminate CE even if
! CE_rel_rlo_for_detachment has not been reached.
! If set to a large number mass loss will only stop when the star definitely wants
! to detach. If set to a low number system will likely switch to stable mass transfer.

! ::

   CE_years_detached_to_terminate = 1d-1


! CE_begin_at_max_implicit_abs_mdot
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! If true, initiate a common envelope phase when max_implicit_abs_mdot is reached

! ::

   CE_begin_at_max_implicit_abs_mdot = .false.


! CE_xa_diff_to_terminate
! ~~~~~~~~~~~~~~~~~~~~~~~

! If the absolute difference between central and surface mass fractions of H and He
! is below this, terminate the simulation. This is to stop the simulation once the entire
! envelope has been removed

! ::

   CE_xa_diff_to_terminate = 0.01d0


! CE_terminate_when_core_overflows
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Terminate if, for the current orbital separation, the radius at the point
! where ``CE_xa_diff_to_terminate`` applies would overflow its Roche lobe

! ::

   CE_terminate_when_core_overflows = .true.


! CE_min_period_in_days
! ~~~~~~~~~~~~~~~~~~~~~

! Terminate the simulation if the period is below this during CE
! used to terminate the simulation early in cases where a merger would be expected.

! ::

   CE_min_period_in_minutes = 5d0


! CE_energy_factor_HII_toHI
! ~~~~~~~~~~~~~~~~~~~~~~~~~

! Recombination energy for ionized hydrogen will be multiplied by this
! factor when computing the energy.

! ::

   CE_energy_factor_HII_toHI = 1d0


! CE_energy_factor_HeII_toHeI
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Recombination energy for singly ionized helium will be multiplied by
! this factor when computing the energy.

! ::

   CE_energy_factor_HeII_toHeI = 1d0


! CE_energy_factor_HeIII_toHeII
! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

! Recombination energy for doubly ionized helium will be multiplied by
! this factor when computing the energy.

! ::

   CE_energy_factor_HeIII_toHeII = 1d0


! CE_energy_factor_H2
! ~~~~~~~~~~~~~~~~~~~

! Dissociation energy for molecular hydrogen will be multiplied by this
! factor when computing the energy.

! ::

   CE_energy_factor_H2 = 0d0


! CE_fixed_lambda
! ~~~~~~~~~~~~~~~

! For comparison to rapid-pop-synth, if this is larger than zero, then compute
! the binding energy from this value of lambda rather than by integrating through
! the envelope

! ::

   CE_fixed_lambda = -1d0

! miscellaneous controls
! ======================


! keep_donor_fixed
! ~~~~~~~~~~~~~~~~

! keep star 1 as donor, even if accretor is closer to filling roche lobe

! ::

   keep_donor_fixed = .true.


! mdot_limit_donor_switch
! ~~~~~~~~~~~~~~~~~~~~~~~

! Do not change donor if mass transfer is larger than this (given in Msun/secyer).
! Avoids erratic changes when both stars are filling their Roche lobes.

! ::

   mdot_limit_donor_switch = 1d-20


! tidal_deformation
! ~~~~~~~~~~~~~~~~~

! Use the tidal deformation corrections fp/ft and the specific moments of inertia irot
! based on binary Roche geometry integrations of Fabry et al., 2022, A&A 661, A123
! This uses the methodology of Kippenhahn and Thomas, 1970, IAU Proc. 4, and Endal and Sofia, 1976, ApJ 210, 184-198
! to represent the stellar structure on equipotential surfaces. In these coordinates, all radii are volume equivalent
! radii.

! ::

   use_tidal_deformation = .false.
   f_sync_switch_from_rot_defor = 8d-1
   f_sync_switch_width = 1d-1
   f_sync_switch_lim = 1d-2

! use_other_{hook}
! ~~~~~~~~~~~~~~~~

! Logicals to deploy the use_other routines.

! ::

   use_other_rlo_mdot = .false.
   use_other_check_implicit_rlo = .false.
   use_other_implicit_function_to_solve = .false.
   use_other_tsync = .false.
   use_other_sync_spin_to_orbit = .false.
   use_other_mdot_edd = .false.
   use_other_adjust_mdots = .false.
   use_other_accreted_material_j = .false.
   use_other_jdot_gr = .false.
   use_other_jdot_ml = .false.
   use_other_jdot_ls = .false.
   use_other_jdot_missing_wind = .false.
   use_other_jdot_mb = .false.
   use_other_extra_jdot = .false.
   use_other_binary_wind_transfer = .false.
   use_other_edot_tidal = .false.
   use_other_edot_enhance = .false.
   use_other_extra_edot = .false.
   use_other_CE_init = .false.
   use_other_CE_rlo_mdot = .false.
   use_other_CE_binary_evolve_step = .false.
   use_other_CE_binary_finish_step = .false.
   use_other_e2 = .false.

! x_ctrl
! ~~~~~~

! extra params as a convenience for developing new features
! use ``x_ctrl`` for floats, ``x_integer_ctrl`` for integers, ``x_logical_ctrl`` for booleans,
! and ``x_character_ctrl`` for strings.
! note: the parameter ``binary_num_x_ctrls`` is defined in ``binary_def.f90``

! ::

   x_ctrl(1:binary_num_x_ctrls) = 0d0
   x_integer_ctrl(1:binary_num_x_ctrls) = 0
   x_logical_ctrl(1:binary_num_x_ctrls) = .false.
   x_character_ctrl(1:binary_num_x_ctrls) = ''