An arc chamber has a liner operably coupled to body. The liner has a second surface recessed from a first surface and a hole having a first diameter. The liner has a liner lip extending upwardly from the second surface toward the first surface that surrounds the hole and has a second diameter. An electrode has a shaft and head. The shaft has a third diameter that is less than the first diameter and passes through the body and hole and is electrically isolated from the liner by an annular gap. The head has a fourth diameter and a third surface having an electrode lip extending downwardly from the third surface toward the second surface. The electrode lip has a fifth diameter that is between the second and fourth diameters. A spacing between the liner lip and electrode lip defines a labyrinth seal and generally prevents contaminants from entering the annular gap. The shaft has an annular groove configured to accept a boron nitride seal.

A charged particle beam apparatus including a winding aberration corrector capable of correcting a chromatic aberration is provided. A multi-pole lens includes a magnetic core 150, a plurality of current lines 101 to 112, a plurality of wire-shaped electrodes 301 to 312, insulating electrode fixing portions 313 to 342 for fixing the plurality of electrodes to a structure in a vacuum container, and conductive shields 320, 321 set to a reference potential, which are provided between the electrode fixing portion and a central axis of the magnetic core, main line portions of the plurality of current lines are arranged axisymmetrically with respect to the central axis of the magnetic core along an inner wall of the magnetic core, and portions of the plurality of electrodes parallel to the central axis of the magnetic core are arranged axisymmetrically with respect to the central axis of the magnetic core.

A charged particle beam source that may include an emitter that has a tip for emitting charged particles; a socket; electrodes; a filament that is connected to the electrodes and to the emitter; electrodes for providing electrical signals to the filament; a support element that is connected to the emitter; and a support structure that comprises one or more interfaces for contacting only a part of the support element while supporting the support element.

A charged particle beam source that may include an emitter that has a tip for emitting charged particles; a socket; electrodes; a filament that is connected to the electrodes and to the emitter; electrodes for providing electrical signals to the filament; a support element that is connected to the emitter; and a support structure that comprises one or more interfaces for contacting only a part of the support element while supporting the support element.

A charged particle beam source that may include an emitter that has a tip for emitting charged particles; a socket; electrodes; a filament that is connected to the electrodes and to the emitter; electrodes for providing electrical signals to the filament; a support element that is connected to the emitter; and a support structure that comprises one or more interfaces for contacting only a part of the support element while supporting the support element.

A charged particle beam source that may include an emitter that has a tip for emitting charged particles; a socket; electrodes; a filament that is connected to the electrodes and to the emitter; electrodes for providing electrical signals to the filament; a support element that is connected to the emitter; and a support structure that comprises one or more interfaces for contacting only a part of the support element while supporting the support element.

The present invention relates to a charged particle beam apparatus enabling a selection of a charged particle beam in a specified energy range by symmetrically arranging cylindrical electrostatic lenses deflecting a path of the charged particle beam and disposing an energy selection aperture between the cylindrical electrostatic lenses. Since an integral structure in which a central electrode and a plurality of electrodes that are arranged at a front portion and a rear portion in relation to the central electrode of a monochromator are fixed to each other through insulator, is applied, a mechanism for adjusting an offset with respect to an optical axis is simplified as compared to the case of separately providing the lenses at the front portion and the rear portion, respectively, and a secondary aberration is canceled in an exit plane due to symmetry of an optical system.

The present invention relates to an electron gun cathode mount adapted at one end to secure a thermionic cathode and at the other end to be connected to an attachment member, wherein the electron gun cathode mount is structured so as to be capable of, when in use, reducing heat transfer from the thermionic cathode to the attachment member, and the material forming the electron gun cathode mount has a thermal conductivity of less than 10 Wm.sup.?1K.sup.?1 at the operating temperature of the thermionic cathode in a direction from the thermionic cathode to the attachment member. The present invention also relates to an electron gun assembly having the electron gun cathode mount installed therein.

An arc chamber liner has first and second surfaces and a hole having a first diameter. A liner lip having a second diameter extends upwardly from the second surface toward the first surface and surrounds the hole. An electrode has a shaft with a third diameter and a head with a fourth diameter. The third diameter is less than the first diameter and passes through the body and hole and is electrically isolated from the liner by an annular gap. The head has a third surface having an electrode lip extending downwardly from the third surface toward the second surface. The electrode lip has a fifth diameter between the second and fourth diameters. A spacing between the liner and electrode lips defines a labyrinth seal to generally prevent contaminants from entering the annular gap. The shaft has an annular groove configured to accept a boron nitride seal.

An electron emission tube includes a housing in which an internal space is provided and which keeps the internal space in vacuum, an electron source that is arranged on a first end side in one direction of the housing and that generates an electron, a gate valve that is arranged on a second end side in the one direction of the housing and that can switch the second end side between an open state and a blocked state, and a partition part that is placed between the electron source and the gate valve and that divides the internal space into a first region including the electron source and a second region including the gate valve. The partition part includes an electron-permeable membrane that transmits an electron.