SELECTIVE PRODUCTION OF DOUBLY-EXCITED SPECTRA

Core-excited ions have been produced using charge exchange between met astable ion beams and alkalimetal atoms. The technique used permits an unambiguous discrimination between lines of doubly excited states and those of singly excited states. Other Lines have been determined in t he quartet system of lithiumlike nitrogen (Nv*). Among them are trans itions from high-lying levels (1s2ln'l' with n' greater than or equal to 6) and an electric quadrupole (E2) transition. The spectroscopic so urce can be useful for a wide range of applications. [S1050-2947(97)06 210-0].