Abstract
The theory is given for the excitation of Li-like ions by electron impact. The transitions of interest in this paper are those in which the optical electron only is excited while the (1s)2 core is left unexcited. For such transitions the theory follows closely that for hydrogen-like ions. The theory is applied to transitions induced by electron impact between the 2s, 2p, 3s, 3p and 3d states of N V between threshold and 435.36 eV. The majority of the calculations are carried out in the Coulomb-Born approximation and conclusions are drawn about the accuracy of the results by comparing with strong-coupling and close-coupling calculations. A discussion is given of the importance of these cross sections in the temperature measurement of a laboratory plasma.