State-to-state electron impact cross sections for BeH+molecular ions in ITER-like fusion edge plasmas with Be walls

BeH + molecules will be an important intermediary species present in fusion plasmas with Be walls (e.g. JET, ITER), both for impurity transport and spectroscopic studies. To enable such analyses the electron-impact-induced excitations X 1 Σ + ( v i ) → A 1 Σ + ( v f ) and X 1 Σ + ( v i ) → B 1 Π( v f ) in BeH + ( v i ) molecular ion, occurring between the v i and v f vibrational levels of different electronic states (vibro-electronic transitions), have been studied using the Coulomb–Born approximation. The cross sections and rate coefficients for these transitions have been calculated in a broad energy and temperature range, respectively. Accurate analytic fit expressions have been derived for the cross sections and rate coefficients for the v i = v f = 0 case of considered electronic transitions that have correct asymptotic limits. It has been demonstrated that the cross sections and rate coefficients for v i , v f > 0 transitions satisfy approximate (to within 10%) scaling relationships that involve the transition energies and matrix elements of dipole transition moments only.