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Methods and apparatus for generating a strongly-ionized plasma are described. An apparatus for generating a strongly-ionized plasma according to the present invention includes an anode and a cathode that is positioned adjacent to the anode to form a gap there between. An ionization source generates

Methods and apparatus for generating a strongly-ionized plasma are described. An apparatus for generating a strongly-ionized plasma according to the present invention includes an anode and a cathode that is positioned adjacent to the anode to form a gap there between. An ionization source generates a weakly-ionized plasma proximate to the cathode. A power supply produces an electric field in the gap between the anode and the cathode. The electric field generates excited atoms in the weakly-ionized plasma and generates secondary electrons from the cathode. The secondary electrons ionize the excited atoms, thereby creating the strongly-ionized plasma

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1. An apparatus for generating a strongly-ionized plasma in a chamber, the apparatus comprising:an ionization source that generates a weakly-ionized plasma from a feed gas, the weakly-ionized plasma reducing the probability of developing an electrical breakdown condition in the chamber; a power supp

1. An apparatus for generating a strongly-ionized plasma in a chamber, the apparatus comprising:an ionization source that generates a weakly-ionized plasma from a feed gas, the weakly-ionized plasma reducing the probability of developing an electrical breakdown condition in the chamber; a power supply that supplies power to the weakly-ionized plasma though an electrical pulse applied across the weakly-ionized plasma, the electrical pulse having a magnitude and a rise-time that is sufficient to increase the density of the weakly-ionized plasma to generate a strongly-ionized plasma; and a gas line that supplies feed gas to the strongly-ionized plasma, the feed gas diffusing the strongly-ionized plasma, thereby allowing additional power from the pulsed power supply to be absorbed by the strongly-ionized plasma. 2. The apparatus of claim 1 wherein the power supply applies the electrical pulse across the weakly-ionized plasma to excite atoms in the weakly-ionized plasma and to generate secondary electrons, the secondary electrons ionizing the excited atoms, thereby creating the strongly-ionized plasma.3. The apparatus of claim 1 wherein the gas line supplies additional feed gas that exchanges the weakly-ionized plasma while applying the electrical pulse across.4. The apparatus of claim 1 wherein the power supply generates a constant power.5. The apparatus of claim 1 wherein the power supply generates a constant voltage.6. The apparatus of claim 1 wherein the ionization source is chosen from the group comprising an electrode coupled to a DC power supply, an electrode coupled to an AC power supply, a UV source, an X-ray source, an electron beam source, an ion beam source, an inductively coupled plasma source, a capacitively coupled plasma source, and a microwave plasma source.7. The apparatus of claim 1 further comprising a magnet that is positioned to generate a magnetic field proximate to the weakly-ionized plasma, the magnetic field trapping electrons in the weakly-ionized plasma.8. The apparatus of claim 7 wherein the magnet comprises an electro-magnet.9. The apparatus of claim 7 wherein the magnet is movable.10. A method for generating a strongly-ionized plasma in a chamber, the method comprising:ionizing a feed gas to form a weakly-ionized plasma that reduces the probability of developing an electrical breakdown condition in the chamber; supplying power to the weakly-ionized plasma by applying an electrical pulse across the weakly-ionized plasma, the electrical pulse having a magnitude and a rise-time that is sufficient to increase the density of the weakly-ionized plasma to generate a strongly-ionized plasma; and diffusing the strongly-ionized plasma with additional feed gas thereby allowing the strongly-ionized plasma to absorb additional energy from the power supply. 11. The method of claim 10 wherein the applying the electrical pulse across the weakly-ionized plasma excites atoms in the weakly-ionized plasma and generates secondary electrons, the secondary electrons ionizing the excited atoms, thereby creating a strongly-ionized plasma.12. The method of claim 10 further comprising exchanging the weakly-ionized plasma with additional feed gas.13. The method of claim 10 wherein the applying the electrical pulse comprises applying a quasi-static electric field across the weakly-ionized plasma.14. The method of claim 10 further comprising selecting at least one of a pulse amplitude and a pulse width of the electrical pulse in order to increase an ionization rate of the strongly-ionized plasma.15. The method of claim 10 further comprising selecting at least one of a pulse amplitude and a pulse width of the electrical pulse in order to cause the strongly-ionized plasma to be substantially uniform.16. The method of claim 10 wherein the electrical pulse comprises a rise time that is less than about 100V/μsec.17. The method of claim 10 wherein the peak plasma density of the weakly-ionized plasma is less than about 1012 cm?3.18. The method of claim 10 wherein the peak plasma density of the strongly-ionized plasma is greater than about 1012 cm?3.19. The method of claim 10 wherein the ionizing the feed gas comprises exposing the feed gas to one of a static electric field, an pulsed electric field, UV radiation, X-ray radiation, electron beam radiation, and an ion beam.20. The method of claim 10 further comprising generating a magnetic field proximate to the weakly-ionized plasma, the magnetic field trapping electrons in the weakly-ionized plasma.21. An apparatus for generating a strongly-ionized plasma, the apparatus comprising:an anode; a cathode that is positioned adjacent to the anode and forming a gap there between; an ionization source that generates a weakly-ionized plasma proximate to the cathode, the weakly-ionized plasma reducing the probability of developing an electrical breakdown condition between the anode and the cathode; and a power supply that produces an electric field across the gap, the electric field generating excited atoms in the weakly-ionized plasma and generating secondary electrons from the cathode, the secondary electrons ionizing the excited atoms, thereby creating the strongly-ionized plasma. 22. The apparatus of claim 21 wherein the power supply generates a constant power.23. The apparatus of claim 21 wherein the power supply generates a constant voltage.24. The apparatus of claim 21 wherein the electric field comprises a quasi-static electric field.25. The apparatus of claim 21 wherein the electric field comprises a pulsed electric field.26. The apparatus of claim 21 wherein a rise time of the electric field is chosen to increase an ionization rate of the excited atoms in the weakly-ionized plasma.27. The apparatus of claim 21 wherein the strongly-ionized plasma is substantially uniform proximate to the cathode.28. The apparatus of claim 21 wherein a dimension of the gap between the anode and the cathode is chosen to increase an ionization rate of the excited atoms in the weakly-ionized plasma.29. The apparatus of claim 21 wherein the ionization source is chosen from the group comprising an electrode coupled to a DC power supply, an electrode coupled to an AC power supply, a UV source, an X-ray source, an electron beam source, an ion beam source, an inductively coupled plasma source, a capacitively coupled plasma source, and a microwave plasma source.30. The apparatus of claim 21 further comprising a magnet that is positioned to generate a magnetic field proximate to the weakly-ionized plasma, the magnetic field trapping electrons in the weakly-ionized plasma proximate to the cathode.31. A method for generating a strongly-ionized plasma, the method comprising:ionizing a feed gas to generate a weakly-ionized plasma proximate to a cathode, the weakly-ionized plasma reducing the probability of developing an electrical breakdown condition proximate to the cathode; and applying an electric field across the weakly-ionized plasma in order to excite atoms in the weakly-ionized plasma and to generate secondary electrons from the cathode, the secondary electrons ionizing the excited atoms, thereby creating the strongly-ionized plasma. 32. The method of claim 31 wherein the applying the electric field comprises applying a quasi-static electric field.33. The method of claim 31 wherein the applying an electric field comprises applying the electric field at a constant power.34. The method of claim 31 wherein the applying an electric field comprises applying the electric field at a constant voltage.35. The method of claim 31 wherein the applying the electric field comprises applying an electrical pulse across the weakly-ionized plasma.36. The method of claim 35 further comprising selecting at least one of a pulse amplitude and a pulse width of the electrical pulse in order to increase an ionization rate of the strongly-ionized plasma.37. The method of claim 35 further comprising selecting at least one of a pulse amplitude and a pulse width of the electrical pulse in order to cause the strongly-ionized plasma to be substantially uniform in an area adjacent to a surface of the cathode.38. The method of claim 31 wherein the strongly-ionized plasma is substantially uniform proximate to the cathode.39. The method of claim 31 further comprising generating a magnetic field proximate to the weakly-ionized plasma, the magnetic field trapping electrons in the weakly-ionized plasma.40. An apparatus for generating a strongly-ionized plasma in a chamber, the apparatus comprising:means for ionizing a feed gas to form a weakly-ionized plasma that reduces the probability of developing an electrical breakdown condition in the chamber; means for supplying power to the weakly-ionized plasma by applying an electrical pulse across the weakly-ionized plasma, the electrical pulse having a magnitude and a rise-time that is sufficient to increase the density of the weakly-ionized plasma to generate a strongly-ionized plasma; and means for diffusing the strongly-ionized plasma with additional feed gas to allow additional power to be absorbed by the strongly-ionized plasme. 41. An apparatus for generating a strongly-ionized plasma, the apparatus comprising:means for ionizing a feed gas to generate a weakly-ionized plasma proximate to a cathode, the weakly-ionized plasma reducing the probability of developing an electrical breakdown condition proximate to the cathode; and means for applying an electric field across the weakly-ionized plasma in order to excite atoms in the weakly-ionized plasma and to generate secondary electrons from the cathode, the secondary electrons ionizing the excited atoms, thereby creating the strongly-ionized plasma. 42. The apparatus of claim 1 wherein the power supply comprises the ionization source.43. The apparatus of claim 21 wherein the power supply comprises the ionization source.