Stephen B Wilde, 552558 Pienza St, Livermore, CA 94550

6975072, Dec 13, 2005

May 22, 2003

10/443575

Ka-Ngo Leung - Hercules CA, US
Qing Ji - Albany CA, US
Stephen Wilde - Pleasant Hill CA, US

The Regents of the University of California - Oakland CA

H01J007/24
C23C016/00

31511121, 118723 R

A radio frequency (RF) driven plasma ion source has an external RF antenna, i. e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e. g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source.

4994706, Feb 19, 1991

Feb 2, 1987

7/010053

Ka-Ngo Leung - Hercules CA
David Moussa - San Francisco CA
Stephen B. Wilde - Pleasant Hill CA

The United States of America as represented by the United States
Department of Energy - Washington DC

H01J 115
H01J 192

313 30

A directly heated cylindrical lanthanum boride cathode assembly is disclosed which minimizes generation of magnetic fields which would interfere with electron emission from the cathode. The cathode assembly comprises a lanthanum boride cylinder in electrical contact at one end with a central support shaft which functions as one electrode to carry current to the lanthanum boride cylinder and in electrical contact, at its opposite end with a second electrode which is coaxially position around the central support shaft so that magnetic fields generated by heater current flowing in one direction through the central support shaft are cancelled by an opposite magnetic field generated by current flowing through the lanthanum boride cylinder and the coaxial electrode in a direction opposite to the current flow in the central shaft.

4795940, Jan 3, 1989

Oct 14, 1987

7/108327

Ka-Ngo Leung - Hercules CA
Keith C. Gordon - Berkeley CA
Dean O. Kippenham - Castro Valley CA
Peter Purgalis - San Francisco CA
David Moussa - San Francisco CA
Malcom D. Williams - Danville CA
Stephen B. Wilde - Pleasant Hill CA
Mark W. West - Albany CA

The United States of America as represented by the United States
Department of Energy - Washington DC

H01J 114
H01J 116
H01J 1910

313346R

A large area directly heated lanthanum hexaboride (LaB. sub. 6) cathode system (10) is disclosed. The system comprises a LaB. sub. 6 cathode element (11) generally circular in shape about a central axis. The cathode element (11) has a head (21) with an upper substantially planar emission surface (23), and a lower downwardly and an intermediate body portion (26) which diminishes in cross-section from the head (21) towards the base (22) of the cathode element (11). A central rod (14) is connected to the base (22) of the cathode element (11) and extends along the central axis. Plural upstanding spring fingers (37) are urged against an outer peripheral contact surface (24) of the head end (21) to provide a mechanical and electrical connection to the cathode element (11).