Carter Ross Armstrong

US Patent:

8129910, Mar 6, 2012

Filed:

Jun 23, 2009

Appl. No.:

12/490251

Inventors:

David Riley Whaley - San Carlos CA, US
Ramon Duggal - San Bruno CA, US
Carter Michael Armstrong - Danville CA, US

Assignee:

L-3 Communications Corporation - San Carlos CA

International Classification:

H01J 1/52
H01J 5/02

US Classification:

315 85, 31511121, 31511141, 31511181

Abstract:

A system and method of magnetically insulating the cathode of a cold-cathode electron gun is achieved. A strong magnetic field is applied in the vicinity of the cold cathode to deflect and constrain the flow of electrons emitted from structures within the electron gun. The magnetic field largely prevents re-reflected primary and secondary electrons from reaching the cathode, thereby improving the operation and increasing the life of the cold-cathode electron gun. In addition, the insulating magnetic field improves electron beam focusing and enables a reduction in the magnitude of static electric focusing fields employed in the vicinity of the cold cathode, further reducing the electron gun's susceptibility to destructive arcing.

US Patent:

8217577, Jul 10, 2012

Filed:

Aug 31, 2009

Appl. No.:

12/551174

Inventors:

Mark Frederick Kirshner - Redwood City CA, US
Craig Bisset Wilsen - Redwood City CA, US
Richard Donald Kowalczyk - San Francisco CA, US
Carter Michael Armstrong - Danville CA, US

Assignee:

L-3 Communications Corporation - San Carlos CA

International Classification:

H01J 29/46

US Classification:

315 15, 315 514, 315 537

Abstract:

An apparatus and method of modulating an electron beam to induce a high degree of spatial bunching uses multiple control grids located in close proximity to an electron-emitting cathode. An RF field couples to the electron beam in the cathode-grid gap to induce velocity modulation. The electron beam then propagates through a first control grid, allowing the velocity modulation to induce spatial bunching. The electron beam then traverses a gap between the first grid and a second control grid and interacts with the RF field to induce further bunching of the beam. Simulations show that bunching factors of 50:1 may be achieved.