Time-of-flight focusing to second order in three-electrode axially symmetrical lens

is work is dedicated to definition of time-of-flight focusing by energy including second order in three electrode electrostatic axially symmetrical lens. In the same time regime of collimator lens is considered, when the object is situated in its focal plane. Studied system can be used in schemes of time-of-flight mass-spectrometers in which functions of the spatial and the time-of-flight focusing are divided and are executing by different elements. In particular, formation and spatial focusing of particle flows have being carried out by electronic lenses and its time-of-flight focusing by electronic mirror. Coordination of parameters of electronic lens and mirror in such devices made possible of coincident spatial and time-of-flight focusing