Metal electrodes for electric plasma discharge devices
AssigneeGeneral Electric Company
InventorsTimothy John Sommerer, David John Smith
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Abstract
An all-metal electron emissive structure for low-pressure lamps is disclosed. The all-metal electron emissive structure consisting of one or more metal is operable to emit electrons in response to a thermal excitation, wherein an active region of the electron emissive structure under steady state operating conditions has a temperature greater than about 1500 degree K, and wherein the cathode fall voltage in the discharge medium under steady state operating conditions is less than about 100 volts. A lamp including an envelope, an electrode including the all-metal electron emissive structure, and a medium, is also disclosed.
Claims32
An electrode comprising:
- a rod-like structure consisting of one or more metals, and having a tip comprising an active region that is operable to emit electrons in a discharge medium in response to a thermal excitation,
- wherein the tip has a surface area of less than about 10 mm2,
- the active region under steady state operating conditions has a temperature greater than about 1500 degrees K,
- under steady state operating conditions the discharge medium produces a total pressure less than about 2×104 Pascals, and has a cathode fall voltage of less than about 100 volts.
A lamp comprising:
- an envelope;
- a discharge medium disposed within the envelope;
- and
- an electrode, wherein the electrode comprises,
- a rod-like structure with a tip having an active region that is operable to emit electrons in a discharge medium in response to a thermal excitation, wherein the tip has a surface area of less than about 10 mm2,
- the active region under steady state operating conditions has a temperature greater than about 1500 degrees K,
- under steady state operating conditions the discharge medium produces a total pressure less than about 2×104 Pascals, and has a cathode fall voltage of less than about 100 volts.
Dependencies are inferred from the claim text.