Patrick A Roman

US Patent:

8134130, Mar 13, 2012

Filed:

Jul 19, 2010

Appl. No.:

12/839207

Inventors:

Federico A. Herrero - Glenn Dale MD, US
Patrick A. Roman - Washington DC, US

Assignee:

The United States of America as represented by the Administrator of the National Aeronautics and Space Administration - Washington DC

International Classification:

H01J 37/08
H01J 49/10

US Classification:

250427, 250423 R, 250396 R, 31511181

Abstract:

An ion source may include first, second, and third electrodes. The first electrode may be a repeller having a V-shaped groove. The second electrode may be an electron emitter filament disposed adjacent the base of the V-shaped groove. The third electrode may be an anode that defines an enclosed volume with an aperture formed therein adjacent the electron emitter filament. A potential of the first electrode may be less than a potential of the second electrode, and the potential of the second electrode may be less than a potential of the third electrode. A fourth electrode that is disposed between the electron emitter filament and the anode may be used to produce a more collimated electron beam.