"""Routines to calculate the upstream electron temperature."""
import xarray as xr
from ...algorithm_class import Algorithm
from ...unit_handling import Quantity
[docs]
@Algorithm.register_algorithm(return_keys=["separatrix_electron_temp"])
def calc_separatrix_electron_temp(
target_electron_temp: Quantity | xr.DataArray,
q_parallel: Quantity | xr.DataArray,
parallel_connection_length: Quantity | xr.DataArray,
kappa_e0: Quantity | xr.DataArray,
SOL_conduction_fraction: float | xr.DataArray = 1.0,
) -> Quantity | xr.DataArray:
"""Calculate the upstream electron temperature assuming Spitzer-Harm heat conductivity.
Equation 38 from :cite:`stangeby_2018`, keeping the dependence on target_electron_temp.
Args:
target_electron_temp: [eV] :term:`glossary link<target_electron_temp>`
q_parallel: [GW/m^2] :term:`glossary link<q_parallel>`
parallel_connection_length: [m] :term:`glossary link<parallel_connection_length>`
kappa_e0: [W / (eV**3.5 m)] :term:`glossary link<kappa_e0>`
SOL_conduction_fraction: [eV] :term:`glossary link<SOL_conduction_fraction>`
Returns:
separatrix_electron_temp [eV]
"""
return (target_electron_temp**3.5 + 3.5 * (SOL_conduction_fraction * q_parallel * parallel_connection_length / kappa_e0)) ** (2.0 / 7.0)