ion.py 文件源码

def direct_ionization_cross_section(self, energy: u.erg):
        """
        Calculate direct ionization cross-section.

        The cross-sections are calculated one of two ways:

        - Using the method of [1]_ for hydrogenic and He-like ions
        - Using the scaled cross-sections of [2]_ for all other ions

        References
        ----------
        .. [1] Fontes, C. J., et al., 1999, Phys. Rev. A., `59 1329 <https://journals.aps.org/pra/abstract/10.1103/PhysRevA.59.1329>`_
        .. [2] Dere, K. P., 2007, A&A, `466, 771 <http://adsabs.harvard.edu/abs/2007A%26A...466..771D>`_
        """
        is_hydrogenic = (self.atomic_number - self.charge_state == 1) and (self.atomic_number >= 6)
        is_he_like = (self.atomic_number - self.charge_state == 2) and (self.atomic_number >= 10)

        if is_hydrogenic or is_he_like:
            return self._fontes_cross_section(energy)
        else:
            return self._dere_cross_section(energy)