Method and apparatus for producing electrostatic fields by surface currents on resistive materials with applications to charged particle optics and energy analysis

In a method of establishing a non-uniform field in an ethereal medium, the use adjacent to said medium of a resistive material through which a predetermined electric current flow is produced by applying different potentials to said material at spaced locations thereon, said material having prearranged variations in its resistivity, the method comprising the controlled selection by spatial focusing of ions having predetermined physical characteristics in said medium adjacent said material by the electric field so established.

A method of influencing ions in an ethereal medium which comprises the steps of:

• providing within an ethereal medium a structure of hollow configuration having opened ends and parallel sides of uniform resistivity in the range of 10.sup.-2 to 10.sup.8 ohm-centimeters, said opened ends each defining a plane perpendicular to said sides, placing a pair of parallel metal plates across said opened ends whereby said plates are parallel, applying voltages to said plates whereby fringe field effects within said hollow structure between said plates and said sides are eliminated, and providing a pair of spaced apart apertures in one of said plates;
• introducing ions into said structure through one of said apertures;
• causing predetermined large changes in velocity and direction of said ions within said structure by controlling the current density in said sides by their geometry, their resistivity and the voltages applied to said plates, said apertures being spaced apart a predetermined distance, whereby only ions in a predetermined energy range which enter said one aperture exit through the other of said apertures.

A method of generating an electric field for causing controlled movement of ions therethrough, the method comprising the steps of providing a shaped structure composed of a physically self-sustaining material having a resistivity in the range of 10.sup.-2 to 10.sup.8 ohm centimeters;

• applying a voltage differential between two locations on said structure to produce an electric field adjacent said structure;
• introducing ions into said electric field;
• and causing predetermined controlled movement of the ions through said field by controlling the current density produced between said locations in said structure by its geometry, its resistivity and the voltages applied thereto.

Apparatus for generating electric fields for the purpose of causing movement of ions through said fields, the apparatus comprising a shaped structure composed of a physically self-sustaining material for receiving an electric current flow, said material having a resistivity in the range of 10.sup.-2 to 10.sup.8 ohm centimeters;

• a first location on said structure receiving a first voltage;
• a second location on said structure receiving a second voltage different from said first voltage whereby a current flows through said structure from said first location to said second location, said current having a predetermined density in said structure at any location proximate the surface thereof;
• said current density being governed by the geometry of the structure, its resistivity and the selected voltage applied thereto and thereby establishing the strength and direction of the electric field generated by said surface through which the ions to be moved are received.