A model is developed to calculate emission spectrum from plasmas in nonlocal-thermodynamic-equilibrium(NLTE).The populations are obtained with a Collisional Radiative Model and the spectrum is calculated with the Unresolved-TransitionArray(UTA)approximation.The present model is applied to the calculation of emissivity from low-,medium-and high-Z plasmas.The integrated emissivity and the spectra are compared with those calculated by other theoretical models.In general speaking,the present results of the mean charge state and emissivity agree well with some theoretical ones while large differences are found when all the theoretical results are included.
