A novel combined focusing-deflection system for streak image tube

A novel multiple-electrode electrostatic deflector (petal-like) is introduced. It can be got by symmetrically slotting a cylindrical electrode into eight separate parts. The Fourier analysis of the potential distribution on the circumference of the electrode circle has elicited the principle for electrode potential settings to generate a nearly transversely-uniform deflecting field. Based on the rotational symmetry in its shape and the harmonicity of the solution of Laplace equation, multipole fields generated by the petal-like electrode would not affect the focusing property of the conventional electrostatic lens in the paraxial region, when the focusing potential additionally applied. Therefore, the introduced multiple-electrode petal-like defector can be combined with the commonly used