Time-of-flight focusing in triode axisymmetric electrostatic lens up to second order (inclusive)

In the problems of the space focusing of stationary charged particles fluxes, the most prevailing lenses used are the axisymmetric and electrostatic. Their electronic and optical properties in this relation are fully studied. This paper describes a method to define the conditions of the time-of-flight charged particles focusing by the energy in the triode axisymmetric electrostatic lens designed in form of the coaxial cylinders with an equal diameter. The range of electrode configuration and potential variations, that make the focusing possible, are very wide