Non L.T.E. populations and related quantities for H-H--e plasmas as a function of the cut-off level

Abstract The influence of the choice of the cut-off level n* of the evaluation of the coefficients of quasistationary plasmas has been studied. The numerical results show that the coefficient r1(i) which represents the contribution of the population density of the ith excited level by direct excitation from the ground level, is strongly affected by the choice of n*. A minor influence is observed 1) on the coefficient r 0 (i) which represents the contribution to the population density of the ith level from the continuum of free electrons 2) on the collisional-radiative recombination (α) and ionization (S) coefficients'.