US 5,686,785 AGranted

Electron gun having electrically isolated and adjustable cathode

AssigneeMishznarodnii Zentr Elektronno-Prome-newikh Tekhnologii IES im. E.O. Patona NAN

InventorsBoris A. Movchan, Viktor A. Timashov, Evgenii L. Pijuk

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Abstract

An electron gun for producing a beam of electrons has an elongated, linear thermionic cathode and a focusing electrode. The opposite ends of the cathode are engaged by adjustable holders which enable the spatial separation between the cathode and focusing electrode to be easily varied. The focusing electrode is electrically isolated from the cathode whereby fine tuning of the electron beam may be accomplished by varying the potential difference between the focusing electrode and cathode.

Claims20

Dependent claims

An electron gun comprising:

an elongated thermionic source of electrons, said source defining an axis and having oppositely disposed first and second end portions;
housing means;
a first electrically conductive holder for engaging and supporting said first end portion of said electron source;
first mounting means for adjustably mounting said first holder from said housing means, said first mounting means being at least in part electrically conductive whereby current for heating said electron source may flow through said first mounting means and first holder;
a second electrically conductive holder for engaging and supporting said second end portion of said electron source;
second adjustable mounting means for resiliently mounting said second holder from said housing means, said second mounting means being at least in part electrically conductive whereby current for heating said electron source may flow through said second mounting means and second holder;
insulating means carried by said housing means for electrically isolating said first mounting means from said second mounting means;
a focusing electrode positioned in proximity to and spaced from said electron source, said focusing electrode extending along a substantial portion of the length of said electron source in the region disposed between said holders, said focusing electrode having a surface which is substantially parallel to the axis defined by said elongated electron source;
means for supporting said focusing electrode from said housing means, said supporting means engaging said insulating means whereby said focusing electrode support is electrically isolated from said electron source;
and
at least a first accelerating electrode, said first accelerating electrode being positioned a predetermined distance from said electron source in the direction of travel of electrons focused by the action of said focusing electrode, said accelerating electrode being electrically isolated from said electron source and focusing electrode.

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Dependencies are inferred from the claim text.

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Abstract

An electron gun comprising:

an elongated thermionic source of electrons, said source defining an axis and having oppositely disposed first and second end portions;
housing means;
a first electrically conductive holder for engaging and supporting said first end portion of said electron source;
first mounting means for adjustably mounting said first holder from said housing means, said first mounting means being at least in part electrically conductive whereby current for heating said electron source may flow through said first mounting means and first holder;
a second electrically conductive holder for engaging and supporting said second end portion of said electron source;
second adjustable mounting means for resiliently mounting said second holder from said housing means, said second mounting means being at least in part electrically conductive whereby current for heating said electron source may flow through said second mounting means and second holder;
insulating means carried by said housing means for electrically isolating said first mounting means from said second mounting means;
a focusing electrode positioned in proximity to and spaced from said electron source, said focusing electrode extending along a substantial portion of the length of said electron source in the region disposed between said holders, said focusing electrode having a surface which is substantially parallel to the axis defined by said elongated electron source;
means for supporting said focusing electrode from said housing means, said supporting means engaging said insulating means whereby said focusing electrode support is electrically isolated from said electron source;
and
at least a first accelerating electrode, said first accelerating electrode being positioned a predetermined distance from said electron source in the direction of travel of electrons focused by the action of said focusing electrode, said accelerating electrode being electrically isolated from said electron source and focusing electrode.

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