Claims
- 1. An ion pump, comprising:an anode including multiple anode cells, the anode cells being shaped so that the plasma sheath substantially conforms to the anode walls and the anode cells arranged so as to eliminate intracellular voids; a source of a magnetic field for maintaining the plasma within the anode cells; two cathodes, one cathode positioned on either side of and spaced apart from the anode; and a source of an electric field for accelerating particles to sputter the cathode.
- 2. The ion pump of claim 1 in which the anode cells are quasi-cylindrical.
- 3. The ion pump of claim 2 in which the anode cell has a minimum diameter and in which the diameter of the anode cell is less than or equal to about two electron cyclotron radii throughout most of the anode cell.
- 4. The ion pump of claim 1 in which at last some of the walls of different ones of the multiple anode cells are formed from a single piece of metal.
- 5. An ion pump, comprising:an anode including multiple non-rectangular anode cells, the anode cells being arranged to eliminate gaps between the multiple anode cells; a source of a magnetic field for maintaining the plasma within the anode cells; two cathodes, one cathode positioned on either side of and spaced apart from the anode; a source of an electric field between the anode and the cathode for accelerating particles to sputter the cathode.
- 6. The ion pump of claim 5 in which the anode cells include arcuate walls.
- 7. The ion pump of claim 5 in which the anode cells are quasi-cylindrical in shape.
- 8. The ion pump of claim 7 in which the anode cell has a minimum diameter and in which the diameter of the anode cell is less than or equal to about two electron cyclotron radii throughout most of the anode cell.
- 9. A method of evacuating a chamber using an ion pump, comprising:providing an anode having multiple, non-rectangular anode cells, the cells being packed without interstices in the anode; applying a magnetic field for maintaining a plasma in the anode cells; providing a cathode including material for sputtering to remove gas from the ion pump environment; applying an electric field between the anode and cathode, the electric field accelerating ionized gas particles toward cathode into at least one impact area defined by the at least one anode cell.
- 10. The method of claim 9 in which providing an anode having multiple, non-rectangular anode cells includes providing an anode having quasi-cylindrical anode cells.
- 11. The method of claim 10 in which providing an anode having quasi-cylindrical anode cells includes providing an anode having cells in which, in each anode cell, the diameter of the cell is within about two electron cyclotron radii throughout most of the anode cell.
- 12. A charged particle beam system exhibiting improved stability, comprising:a source of charged particles; charge particle optics for forming the charged particles into a beam; a vacuum system for creating an evacuated environment for the charged particle beam, the vacuum system including an ion pump including an anode having non-rectangular anode cells arranged without gaps between them to form the anode, thereby reducing instabilities of the charged particle beam.
- 13. The charged particle beam system of claim 12 in which the source of charged particles comprises a source of ions.
- 14. The charged particle beam system of claim 12 in which the source of charged particles comprises a source of electrons.
- 15. An anode for an ion pump having multiple anode cells, each cell having a shape in which the anode sheath conforms to the anode walls sufficiently to allow efficient transfer of electrons to the anode while minimizing or eliminating the inter-cylindrical cell.
- 16. The anode of claim 15 in which each cell has a quasi-cylindrical shape.
- 17. A method of manufacturing an anode for an ion pump, comprising:bending one or more metal strips into a wave pattern; and connecting together sections of the one or more metal strips to form an array of anode cells, the cells having no interstices between them.
- 18. The method of claim 17 in which connecting together sections includes welding sections together.
- 19. The method of claim 17 in which the one or more metal strips comprise multiple metal strips, the multiple strips being connected to form the array of quasi-cylindrical cells.
- 20. The method of claim 17 in which the one or more metal strips comprise multiple metal strips, the multiple strips being connected to form the array of quasi-cylindrical cells.
- 21. The method of claim 17 in which the one or more metal strips comprises a single metal strip, the single metal strip folding back on itself to form an array of quasi-cylindrical cells.
RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application Nos. 60/125,317 and 60/125,318 both of which are hereby filed Mar. 19, 1999, which are hereby incorporated by reference.
US Referenced Citations (5)
Non-Patent Literature Citations (3)
Entry |
“Ion Pumps”, Varian-Vacuum Products; http://www.vvp.varian.com/products/ion.htm; Varian Associates, Jan. 1998. |
“Technical Notes-Ion Pumps”, Varian-Vacuum Products-Technical Notes; http://www.vvp.varian.com/technotes/ion.htm; Varian Associates, Inc., Jan. 1998. |
“Theory of Operation” Thermionics Vacuum Products; http://www.thermionics.com/ip-too.htm; Mar. 23, 1998. |
Provisional Applications (2)
|
Number |
Date |
Country |
|
60/125318 |
Mar 1999 |
US |
|
60/125317 |
Mar 1999 |
US |