Claims
- 1. A particle injector for charging and ejecting dielectric particles or droplets, comprising:
- a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- a grid member located adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- means for biasing said grid member at a high voltage with respect to said plate member; and
- means for providing and directing ultraviolet light onto said surface of said plate member upon which dielectric particles or droplets may be placed to cause photoelectrons to be emitted from said plate member.
- 2. A particle injector as defined in claim 1, wherein said plate member is made of a material from the group consisting of zinc and nickel.
- 3. A particle injector as defined in claim 1, wherein said surface of said plate member is flat.
- 4. A particle injector as defined in claim 3, wherein said grid member is flat and parallel to said surface of said plate member.
- 5. A particle injector as defined in claim 1, wherein said grid member comprises: a highly transparent, coarse wire grid.
- 6. A particle injector as defined in claim 1, wherein said grid member is spaced approximately one to two centimeters away from said surface of said plate member.
- 7. A particle injector as defined in claim 6, wherein said grid member is spaced approximately two centimeters away from said surface of said plate member.
- 8. A particle injector as defined in claim 1, wherein said biasing means comprises:
- a high voltage DC power supply having a positive side and a negative side.
- 9. A particle injector as defined in claim 8, wherein said high voltage DC power supply provides a variable DC output voltage.
- 10. A particle injector as defined in claim 8, wherein said positive side of said high voltage DC power supply is electrically connected to said grid member, and wherein said negative side of said high voltage DC power supply is electrically connected to said plate member.
- 11. A particle injector as defined in claim 10, wherein said high Voltage DC power supply biases said grid member to approximately 1000 Volts with respect to said plate member.
- 12. A particle injector as defined in claim 1, wherein said means for providing and directing ultraviolet light comprises:
- a lamp for providing ultraviolet light; and
- means for focusing and directing said ultraviolet light from said lamp onto said surface of said plate member.
- 13. A particle injector as defined in claim 12, wherein said lamp generates ultraviolet light having a wavelength of between approximately 2000 and 3000 Angstroms.
- 14. A particle injector as defined in claim 12, wherein said lamp comprises:
- a Mercury arc lamp.
- 15. A particle injector as defined in claim 12, wherein said means for providing and directing ultraviolet light additionally comprises:
- means for altering the characteristics of the ultraviolet light provided by said lamp.
- 16. A particle injector as defined in claim 15, wherein said altering means causes ultraviolet light directed onto said surface of said plate member to have a wavelength of between approximately 2000 and 3000 Angstroms.
- 17. A particle injector as defined in claim 1, additionally comprising:
- means for containing said plate member and said grid member, said containing means having a vacuum therein.
- 18. A particle injector as defined in claim 1, additionally comprising:
- a shield grid located adjacent to and spaced away from the side of said grid member opposite said plate member, said shield grid being made of a conductive material.
- 19. A particle injector as defined in claim 18, wherein said shield grid is electrically connected to said plate member.
- 20. A particle injector for charging and ejecting dielectric particles or droplets, comprising:
- a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- a grid member located adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- means for biasing said grid member at a high positive voltage with respect to said plate member; and
- means for providing and directing ultraviolet light having a wavelength between 2000 and 3000 Angstroms onto said surface of said plate member upon which dielectric particles or droplets may be placed to cause photoelectrons to be emitted from said plate member, said photoelectrons becoming attached to said dielectric particles or droplets to cause said dielectric particles or droplets to become negatively charged.
- 21. A particle injector for charging and ejecting dielectric particles or droplets, comprising:
- a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- a grid member located adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- means for biasing said grid member at a high voltage with respect to said plate member; and
- means for providing and directing ultraviolet light onto said surface of said plate member upon which dielectric particles or droplets may be placed to cause photoelectrons to be emitted from said plate member, thereby causing dielectric particles or droplets on said surface of said plate member to become charged and to be ejected from said surface of said plate member. PG,25
- 22. A method of charging and ejecting dielectric particles or droplets, comprising:
- providing a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- locating a grid member adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- biasing said grid member at a high voltage with respect to said plate member; and
- directing ultraviolet light onto said surface of said plate member upon which dielectric particles or droplets may be placed to cause photoelectrons to be emitted from said plate member.
- 23. A method of charging and ejecting dielectric particles or droplets, comprising:
- providing a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- locating a grid member adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- biasing said grid member at a high voltage with respect to said plate member; and
- directing ultraviolet light onto said surface of said plate member upon which dielectric particles or droplets may be placed to cause photoelectrons to be emitted from said plate member, thereby causing dielectric particles or droplets on said surface of said plate member to become charged and to be ejected from said surface of said plate member.
- 24. A particle injector for charging and ejecting dielectric particles or droplets, comprising:
- a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- a grid member located adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- means for biasing said grid member at a high voltage with respect to said plate member; and
- a Kaufman ion source for directing a beam onto said surface of said plate member, thereby causing dielectric particles or droplets on said surface of said plate member to become charged and to be ejected from said surface of said plate member.
- 25. A method of charging and ejecting dielectric particles or droplets, comprising:
- providing a plate member made of a material which has a low work function, said plate member having a surface upon which dielectric particles or droplets may be placed;
- locating a grid member adjacent to and spaced away from said surface of said plate member upon which dielectric particles or droplets may be placed, said grid member being made of a conductive material;
- biasing said grid member at a high voltage with respect to said plate member; and
- directing a beam from a Kaufman ion source onto said surface of said plate member, thereby causing dielectric particles or droplets on said surface of said plate member to become charged and to be ejected from said surface of said plate member.
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA Contract, and is subject to the provisions of Public Law 96-517 (35 U.S.C. 202) in which the Contractor has elected to retain title.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4255777 |
Kelly |
Mar 1981 |
|
4748043 |
Seaver et al. |
May 1988 |
|
4918468 |
Miekka et al. |
Apr 1990 |
|