Robert C Roman

US Patent:

42186331, Aug 19, 1980

Filed:

Oct 23, 1978

Appl. No.:

5/953391

Inventors:

Michael J. Mirtich - N. Olmsted OH
James S. Sovey - Strongsville OH
Robert F. Roman - Brookpark OH

Assignee:

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

International Classification:

H01J 1726

US Classification:

313362

Abstract:

A source of hydrogen ions is disclosed and includes a chamber having at one end a cathode which provides electrons and through which hydrogen gas flows into the chamber. Screen and accelerator grids are provided at the other end of the chamber. A baffle plate is disposed between the cathode and the grids and a cylindrical baffle is disposed coaxially with the cathode at the one end of the chamber. The cylindrical baffle is of greater diameter than the baffle plate to provide discharge impedance and also to protect the cathode from ion flux. An anode electrode draws the electrons away from the cathode. The hollow cathode includes a tubular insert of tungsten impregnated with a low work function material to provide ample electrons. A heater is provided around the hollow cathode to initiate electron emission from the low work function material.

US Patent:

57118604, Jan 27, 1998

Filed:

Jan 25, 1996

Appl. No.:

8/591125

Inventors:

Kenneth A. Jensen - Bay Village OH
Arthur N. Curren - North Ridgeville OH
Robert F. Roman - Brook Park OH

Assignee:

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

International Classification:

C23C 1434

US Classification:

20419211

Abstract:

The present invention is directed to a method and apparatus for producing a highly-textured surface on a copper substrate with only extremely small amounts of texture-inducing seeding or masking material. The texture-inducing seeding material is delivered to the copper substrate electrically switching the seeding material in and out of a circuit loop.

US Patent:

44662424, Aug 21, 1984

Filed:

Mar 9, 1983

Appl. No.:

6/473498

Inventors:

James S. Sovey - Strongsville OH
Vincent K. Rawlin - Wellington OH
Robert F. Roman - Brook Park OH

Assignee:

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

International Classification:

F03H 500

US Classification:

60202

Abstract:

An improved ion thruster (10) for low specific impulse operation in the 1500 sec to 6000 sec range has a multicusp boundary field (48) provided by high strength magnets (30-38) on an iron anode shell (14) which lengthens the paths of electrons from a hollow cathode assembly (20). A downstream anode pole piece in the form of an iron ring (40) supports a ring of magnets (44) to provide a more uniform beam profile. A cylindrical cathode magnet (46) can be moved selectively in an axial direction along a feed tube (22) to produce the desired magnetic field at the cathode tip (24).

US Patent:

60715952, Jun 6, 2000

Filed:

Jan 24, 1996

Appl. No.:

8/605296

Inventors:

Kenneth A. Jensen - Bay Village OH
Arthur N. Curren - North Ridgeville OH
Robert F. Roman - Brook Park OH

Assignee:

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

International Classification:

B32B 900

US Classification:

428195

Abstract:

The present invention is directed to a method and apparatus for producing a highly-textured surface on a copper substrate with only extremely small amounts of texture-inducing seeding or masking material. The texture-inducing seeding material is delivered to the copper substrate electrically switching the seeding material in and out of a circuit loop.