Neutrino Losses
We model thermal neutrino losses (plasma, photo-, pair-, recombination, and Bremsstrahlung) using the method described in [40]. This neutrino loss term is included in all of the reaction networks by default, and modifies the energy equation to have the form (for Strang splitting):
where \(\epsilon_\nu\) are the thermal neutrino losses.
Note
Thermal neutrino losses can be disabled at compile time by setting the make
variable USE_NEUTRINOS = FALSE
.
The interface for the neutrino loss function is:
template <int do_derivatives>
AMREX_GPU_HOST_DEVICE AMREX_INLINE
void sneut5(const amrex::Real temp, const amrex::Real den,
const amrex::Real abar, const amrex::Real zbar,
amrex::Real& snu, amrex::Real& dsnudt, amrex::Real& dsnudd,
amrex::Real& dsnuda, amrex::Real& dsnudz)
Here, the template parameter, do_derivatives
, can be used to disable the code
the computes the derivatives of the neutrino loss, for example, if a numerical Jacobian
is used. The output is
snu
: \(\epsilon_\nu\), the neutrino loss in erg/g/sdsnudt
: \(d\epsilon_\nu/dT\)dsnudd
: \(d\epsilon_\nu/d\rho\)dsnuda
: \(d\epsilon_\nu/d\bar{A}\)dsnudz
: \(d\epsilon_\nu/d\bar{Z}\)
By default, we do not include the recombination terms when calculating the total losses since its effect is negligible.
This is controlled by the include_recomb
parameter defined in Microphysics/neutrinos/_parameters
.
To include the recombination terms, set neutrino_cooling.include_recomb = 1
in the inputs file.