Positron interaction with beryllium and its compounds BeX (X = H, N, O)

Abstract

Beryllium is chosen as one of the plasma-facing wall materials for fusion devices like the International Thermonuclear Experimental Reactor and Joint European Torus. Positron interaction with Be and its compounds, leading to various molecular processes, is essential for modeling plasma reactions. In the present work, we investigate elastic and inelastic (positronium formation, excitation, and direct ionization) processes for positron interaction with Be and BeX (X = H, N, O) over a wide energy range from circa 1 eV to 5 keV. The results are derived using a quantum mechanical Spherical Complex Optical Potential approach aided by the Complex Scattering Potential-ionization contribution formalism. We quantified positron-driven molecular processes through summed electronic excitation (∑Qexc), positronium formation (QPs), direct ionization (QD−ion), elastic (Qel), inelastic (Qinel), and total (QT) cross sections. Since this is the first effort to report positron interaction ionization for Be compounds, we have evaluated QD−ion also using the Binary Encounter Bethe model and found a good comparison. Further, the present work is a maiden report of ∑Qexc, QD−ion, QPs, Qinel, Qel, and QT for BeX (X = H, N, O) compounds.