Patent ID: 9224570
Filing Date: 2015-12-29
Classification: H01J

Abstract:
1. A method for fabricating a diamond amplified cathode capsule for generating an electron beam of secondary electrons, the method comprising: providing a cathode element having a primary emission surface adapted to emit primary electrons; providing an annular insulating spacer; providing a diamond window element comprising a diamond material and having a secondary emission surface adapted to emit secondary electrons in response to primary electrons impinging on the diamond window element; stacking a first high-temperature solder blank between the diamond element and the annular insulating spacer; heating the first high-temperature solder blank under vacuum to form a weld between the diamond element and the annular insulating spacer thereby forming a welded diamond element and annular insulating spacer sub-unit; stacking a second high temperature solder blank between the cathode element and the welded diamond element and annular insulating spacer sub-unit; sealing off the diamond element from the second high temperature solder blank; and heating the second high temperature solder blank under vacuum to form a weld between the cathode element and the welded diamond element and annular insulating spacer sub-unit, thereby forming a vacuum encapsulated, diamond amplified cathode capsule with a hermitically sealed chamber defined therein, wherein the diamond element is protected from out gassing from the second high temperature solder blank during said second heating due to said sealing off of the diamond element.