Cylindrical deflector focusing in two directions

In this paper analytical expressions for the potential distribution inside a cylindrical condenser with edge electrodes are presented. As a deflector this device can focus a beam in two directions. For this case we have obtained simple formulae for the focal power and calculated its value in stigmatic focusing conditions. We have also proposed to use this device as a mirror analyser. Its construction is simpler than the construction of a classical cylindrical analyser with edge electrodes, while the parameters are the same.