Absolute differential cross sections for low-energy He⁺–He collisions via fully quantum dynamics

Angular differential cross sections for elastic scattering and charge transfer in low-energy He⁺–He collisions underpin diverse plasma applications, yet systematic quantum mechanical data remain scarce. Employing the fully quantum mechanical molecular-orbital close-coupling method with high-accuracy ab initio potential energy curves, absolute angular differential cross sections are computed over 0.005–1250 eV/u and scattering angles 0.01°–90°. The present results show good agreement with available high-resolution experimental benchmarks in both magnitude and oscillatory structure, with improved consistency over existing semiclassical and single-electron approaches. By decomposing the cross sections into separate symmetric and antisymmetric channel contributions, three classes of oscillatory structures and their energy evolution are identified: regular oscillations from two-channel quantum interference, irregular oscillations from rainbow scattering in the deep attractive well, and fine-scale oscillations from matter-wave diffraction off the repulsive wall. This work provides the first systematic, fully quantum mechanical differential cross-section dataset across the low-energy and full angular range, serving as reliable reference data for plasma modeling and related applications.