Electron-impact excitation of W44+ and W45+

Plans to employ tungsten in the divertor region of the International Thermonuclear Experimental Reactor require radiative and collisional data for modelling x-ray emissions of highly ionized stages of tungsten. In an earlier paper, we reported on the results of fully relativistic R-matrix calculations for W46+ that included the effects of radiation damping on the resonance contributions. In this paper, we present the results of similar fully relativistic, radiatively damped R-matrix calculations for W44+ and W45+. Radiation damping is found to be small for W45+, but is appreciable for many of the excitations from the ground and metastable levels of W44+. Rates from the present calculations will be combined with those from the calculations for W46+ and employed for collisional-radiative modelling for these ions.