@namespace: network

# We are modeling a reaction of the form
#
#   f + f -> a + gamma
#
# Baryon conservation requires A_f = A_a / 2, and charge conservation
# requires Z_f = Z_a / 2
#
# Our reaction rate has the form
#
#   r = r_0 n_f^2 (T/T_0)^nu     [this has units of cm^3/s]
#
# This is the source for the number density evolution:
#
#   dn_f/dt = -r
#
# Written in terms of mass fractions, this becomes:
#
#   dX_f/dt = - rtilde X_f^2 (rho / rho_0) (T / T_0)^nu
#   dX_a/dt =   rtilde X_f^2 (rho / rho_0) (T / T_0)^nu
#
# where rtilde = r_0 rho_0 / (m_u A_f)  [this has units of 1/s]
# and rho_0 is a reference density and T_0 is a reference
# temperature.
#
# and then the energy generation rate is
#
# eps = -q_burn dX_f/dt              [this has units of erg/g/s]
#
# with q_burn the specific energy release
#
# Since this is a simple power-law, we allow for an activation
# energy, such that r = 0 for T < f_act*T_0

# the coefficient for the reaction rate
rtilde        real    1.e0

# exponent for the temperature
nu            real    4.e0

# reaction specific q-value (in erg/g)
specific_q_burn        real   10.e0

# reaction thresholds (for the power law)
T_burn_ref    real   1.0e0     # T_0 in the notation above
rho_burn_ref  real   1.0e0     # rho_0 in the notation above
f_act         real   1.0e0     # activation T factor (f_act*T_burn_ref)
