Hall-effect motor in which the temperature of the cathode-heating device is controlled

Patent metadata

Field	Value
Publication number	US-9309871-B2
Application number	US-201113643109-A
Country	US
Kind code	B2
Filing date	Apr 29, 2011
Priority date	Apr 29, 2010
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A Hall effect thruster including: a discharge channel with an open downstream end; a cathode situated outside the discharge channel; an injector system configured to inject atoms of gas into the discharge channel, the injector system situated at an upstream end of the discharge channel and also forming a cathode; a heater device configured to heat the cathode; a measurement mechanism measuring temperature of the heater device, and a regulator circuit regulating the temperature such that the heater device heats so long as its temperature is less than a threshold temperature from which the thruster is capable of starting, and ceases to heat shortly after the threshold temperature has been reached.

First claim

The invention claimed is:

1. A Hall effect thruster comprising:
a discharge channel with an open downstream end;
a cathode situated outside the discharge channel;
an injector system configured to inject a atoms of gas into the discharge channel, the injector system being situated at an upstream end of the discharge channel and also forming an anode;
a heater device configured to heat the cathode;
a temperature sensor configured to produce measurements of a temperature of the heater device; and
a regulator circuit configured to regulate the temperature such that the heater device heats until a most recent of the measurements of the temperature reaches a threshold temperature from which the thruster is capable of starting, and ceases to heat shortly after the threshold temperature has been reached,
wherein the injector system injects the gas into the discharge channel after the most recent of the measurements of the temperature reaches the threshold temperature.

2. A Hall effect thruster according to claim 1 , wherein the threshold temperature is a function of a critical magnitude of a discharge current emitted by the cathode, which magnitude corresponds to the thruster starting.

3. A Hall effect thruster according to claim 1 , wherein the temperature of the heater device is determined by measuring electrical resistivity of the heater device.

4. A method of regulating a Hall effect thruster according to claim 1 , the method comprising:
heating the cathode by using the heater device while simultaneously taking measurements of the temperature of the heater device;
continuing the heating of the cathode until the most recent of the measurements of the temperature reaches the threshold temperature from which the thruster is capable of starting; and
injecting the gas into the discharge channel after the most recent of the measurements of the temperature reaches the threshold temperature.

5. A method of regulating a Hall effect thruster according to claim 4 , wherein the threshold temperature is a function of a critical magnitude of a discharge current emitted by the cathode, which magnitude corresponds to the thruster starting.

6. A method of regulating a Hall effect thruster according to claim 5 , wherein, after the most recent of the measurements of the temperature reaches the threshold temperature, and while a magnitude of the discharge current emitted by the cathode is less than the critical magnitude for the discharge current and while a pressure of the gas in the discharge channel is less than a critical pressure, the cathode continues to be heated and the gas continues to be injected into the discharge channel.

7. A method of regulating a Hall effect thruster according to claim 5 , wherein, after the threshold temperature has been reached by the heater device, and while a magnitude of the discharge current emitted by the cathode is less than the critical magnitude for the discharge current and while a pressure of the gas in the discharge channel is less than a critical pressure, at least one voltage pulse is applied to the cathode until the magnitude of the discharge current becomes equal to the critical magnitude for the discharge current so as to enable the thruster to start.

8. A Hall effect thruster according to claim 1 , wherein heating of said cathode is stopped 5 seconds to 300 seconds after the most recent of the measurements of the temperature reaches the threshold temperature.

9. A Hall effect thruster according to claim 1 , wherein heating of said cathode is stopped 5 seconds to 60 seconds after the most recent of the measurements of the temperature reaches the threshold temperature.

Assignees

• Marchandise Frédéric
• Oberg Michael
• Cornu Nicolas
• Snecma

Inventors

• Marchandise Frédéric
• Oberg Michael
• Cornu Nicolas

Classifications

• H05H1/54 Primary

  Plasma accelerators · CPC title

• F03H1/0062

  grid-less with an applied magnetic field · CPC title

• G05D23/24

  the sensing element having a resistance varying with temperature, e.g. a thermistor · CPC title

• H01J1/15

  Cathodes heated directly by an electric current · CPC title

• H01J19/16

  Heaters · CPC title