ELECTRON BEAM GENERATING APPARATUS

• US 20090212681A1
• Filed: 02/08/2007
• Published: 08/27/2009
• Est. Priority Date: 03/10/2006
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Matsumura, Tatsuya
• Granted Patent: US 8,110,974 B2
• Time in Patent Office: Days
• US Class Current: 313/420
• CPC Class Codes: H01J 2237/061 Construction
• CPC Class Codes: H01J 2237/06308 Thermionic sources
• CPC Class Codes: H01J 2237/164 Particle-permeable windows
• CPC Class Codes: H01J 33/04 Windows
• CPC Class Codes: H01J 35/116 Transmissive anodes acting as a window H01J35/186

Abstract

An electron beam generating apparatus (1a) includes an electron gun (2), a vacuum container (3), a frame material (11), and a window material (13). The electron gun (2) has a filament (7) from which an electron beam (EB) is emitted. The vacuum container (3) holds the filament (7). The frame material (11) has an electron passing hole (11c) through which the electron beam (EB) passes, and is detachably attached to the vacuum container (3). The window material (13) is bonded (brazed) to the frame material (11) so as to airtightly stop up the electron passing hole (11c), and allows the electron beam (EB) to penetrate therethrough.

Claims

1. An electron beam generating apparatus comprising:

an electron gun that has an electron emitting member from which an electron beam is emitted;

a container that holds the electron emitting member;

a frame material detachably attached to the container, the frame material having an electron passing hole through which the electron beam passes; and

a window material that is bonded to the frame material so as to airtightly stop the electron passing hole and through which the electron beam penetrates.

2. The electron beam generating apparatus according to claim 1, further comprising:

a sealing member with which a gap between the frame material and the container is airtightly sealed; and

a groove formed on the container side, the groove holding the sealing member.

3. The electron beam generating apparatus according to claim 1, wherein the window material is brazed to the frame material.

4. The electron beam generating apparatus according to claim 1, further comprising a fixing member having an opening through which the electron beam passes, the window material being interposed between the fixing member and the frame material, the fixing member being brazed to the window material and to the frame material.

5. The electron beam generating apparatus according to claim 4,

wherein the frame material has a concave part whose bottom face contains an end of the electron passing hole,

the fixing member is disposed on the bottom face, and

a gap lies between a sidewall of the concave part and a side face of the fixing member.

6. The electron beam generating apparatus according to claim 4, wherein the fixing member is spot-welded to the frame material.

7. The electron beam generating apparatus according to claim 1, wherein the frame material is screwed and fastened to the container.

8. The electron beam generating apparatus according to claim 1, further comprising a presser member that is screwed to the container while pressing the frame material.

9. The electron beam generating apparatus according to claim 1, wherein the frame material is screwed to the container.

10. The electron beam generating apparatus according to claim 1, wherein a width of the electron passing hole faced to the container is expanded in a tapered manner toward an inside of the container.

11. The electron beam generating apparatus according to claim 1, wherein the container has a stepped part by which the frame material is positioned.