Field emission device, field emission method and positioning and fixing method

An electric field radiation device comprising:

• a vacuum enclosure having a vacuum chamber at an inner circumferential side of a tubular insulator whose both ends are sealed;
• an emitter positioned at one side in both end directions in the vacuum chamber and having an electron generating portion that faces the other side in the both end directions of the vacuum chamber;
• a guard electrode arranged at an outer circumferential side of the electron generating portion of the emitter;
• a target positioned at the other side in the both end directions in the vacuum chamber and provided so as to face the electron generating portion of the emitter;
• a movable emitter supporting unit supporting the emitter movably in both end directions of the vacuum chamber;
• an emitter supporting unit female screw bore having an opening on the one side in the both end directions at the emitter supporting unit and extending in the both end directions;
• bellows having a tubular shape having a larger diameter than the emitter supporting unit female screw bore and expanding and contracting in the both end directions, wherein the bellows are arranged so that an axis of the tubular bellows extends coaxially with the screw bore of the emitter supporting unit female screw bore, one end side of the tubular bellows is retained by one side in the both end directions of the vacuum enclosure and the other end side of the tubular bellows is retained by an outer circumferential side of the emitter supporting unit, and form a part of the vacuum chamber;
• an emitter supporting unit operation hole penetrating an inner circumferential side of the bellows in the both end directions at the one side in the both end directions of the vacuum enclosure and extending in the both end directions so that an axis of the emitter supporting unit operation hole is arranged coaxially with the screw bore of the emitter supporting unit female screw bore;
• and
• either one of a position adjustment shaft insertable into the emitter supporting unit operation hole and the emitter supporting unit female screw bore or a pressing shaft insertable into the emitter supporting unit operation hole, wherein
• an opening edge surface of the emitter supporting unit female screw bore extends along a radial direction of the emitter supporting unit female screw bore,
• the emitter supporting unit operation hole has a shape into which one selected from the position adjustment shaft and the pressing shaft is insertable from shaft tip sides of the position adjustment shaft and the pressing shaft,
• the position adjustment shaft is configured to be turned with the position adjustment shaft inserted in the emitter supporting unit operation hole, and is provided, on an outer circumferential surface of a tip of the position adjustment shaft, with a tip side male screw portion configured to be screwed into the emitter supporting unit female screw bore,
• the pressing shaft has, at a tip thereof, a tip surface having a larger diameter than an opening diameter of the emitter supporting unit female screw bore and extending along a radial direction of the pressing shaft,
• the emitter supporting unit operation hole is provided, on an inner circumferential surface at a middle in the both end directions thereof, with an inner circumferential step portion whose diameter is reduced stepwise from the one side toward the other side in the both end directions,
• the pressing shaft is provided, on an outer circumferential surface at a middle in the both end directions thereof, with an outer circumferential step portion whose diameter is reduced stepwise from the one side toward the other side in the both end directions, and
• both of the inner circumferential step portion and the outer circumferential step portion overlap each other in the both end directions, and come into contact with each other when the electron generating portion of the emitter and the guard electrode are brought closer to each other or into contact with each other.

An electric field radiation device comprising:

• a vacuum enclosure having a vacuum chamber at an inner circumferential side of a tubular insulator whose both ends are sealed;
• an emitter positioned at one side in both end directions in the vacuum chamber and having an electron generating portion that faces the other side in the both end directions of the vacuum chamber;
• a guard electrode arranged at an outer circumferential side of the electron generating portion of the emitter;
• a target positioned at the other side in the both end directions in the vacuum chamber and provided so as to face the electron generating portion of the emitter;
• a movable emitter supporting unit supporting the emitter movably in both end directions of the vacuum chamber;
• an emitter supporting unit female screw bore having an opening on the one side in the both end directions at the emitter supporting unit and extending in the both end directions;
• bellows having a tubular shape having a larger diameter than the emitter supporting unit female screw bore and expanding and contracting in the both end directions, wherein the bellows are arranged so that an axis of the tubular bellows extends coaxially with the screw bore of the emitter supporting unit female screw bore, one end side of the tubular bellows is retained by one side in the both end directions of the vacuum enclosure and the other end side of the tubular bellows is retained by an outer circumferential side of the emitter supporting unit, and form a part of the vacuum chamber;
• an emitter supporting unit operation hole penetrating an inner circumferential side of the bellows in the both end directions at the one side in the both end directions of the vacuum enclosure and extending in the both end directions so that an axis of the emitter supporting unit operation hole is arranged coaxially with the screw bore of the emitter supporting unit female screw bore, the emitter supporting unit operation hole comprising:
• a base end portion passage that extends from the one side toward a middle side in the both end directions and expands in two opposing directions of a radial direction of the emitter supporting unit operation hole;
• and
• a hollow portion that bulges outwards in the radial direction of the emitter supporting unit operation hole at the other side in the both end directions of the base end portion passage,
• either one of a position adjustment shaft insertable into the emitter supporting unit operation hole and the emitter supporting unit female screw bore or a pressing shaft insertable into the emitter supporting unit operation hole, wherein
• an opening edge surface of the emitter supporting unit female screw bore extends along a radial direction of the emitter supporting unit female screw bore,
• the emitter supporting unit operation hole has a shape into which one selected from the position adjustment shaft and the pressing shaft is insertable from shaft tip sides of the position adjustment shaft and the pressing shaft,
• the position adjustment shaft is configured to be turned with the position adjustment shaft inserted in the emitter supporting unit operation hole, and is provided, on an outer circumferential surface of a tip of the position adjustment shaft, with a tip side male screw portion configured to be screwed into the emitter supporting unit female screw bore,
• the pressing shaft has, at a tip thereof, a tip surface having a larger diameter than an opening diameter of the emitter supporting unit female screw bore and extending along a radial direction of the pressing shaft,
• the pressing shaft has, at a base end portion thereof, a protruding portion that extends in two opposing directions of the radial direction of the pressing shaft,
• the base end portion passage is shaped so that a diameter thereof is larger than a diameter at the other side in the both end directions of the emitter supporting unit operation hole, and when the pressing shaft inserted in the emitter supporting unit operation hole is in a fixed attitude at an arbitrary angle in a turning direction, the base end portion of the pressing shaft is movable in the both end directions, and
• the hollow portion is shaped so that the base end portion, which is positioned at the other side in the both end directions of the base end portion passage, of the pressing shaft is configured to be turned.