  We study systematically the scattering processes and the conductance spectra
in nodal-line semimetalsuperconductor junctions using the extended
Blonder-Tinkham-Klapwijk theory. The coexistence of peculiar quadruple
reflections are found, which are the specular normal reflection, the
retro-normal reflection, the specular Andreev reflection and the retro-Andreev
reflection. The incident angle dependence and the quasiparticle energy
dependence of the double normal reflections and the double Andreev reflections
are investigated under various values of parameters such as the interfacial
barrier height, the chemical potentials, and the orbital coupling strength. It
is found that the appearance and the disappearance of the reflections and their
magnitudes can be controlled through tuning these parameters. The scattering
mechanism for the reflections are analyzed in details from the viewpoint of the
band structure. We also investigate the conductance spectra for the junctions,
which show distinctive features and strong anisotropy about the orientation
relationships of the nodal line and interface. The unique scattering processes
and conductance spectra found in the junctions are helpful in designing
superconducting electronic devices and searching for the nodal line in
materials experimentally.
