What is a cathode heater, what temperatures do they reach and why are they used in ion thrusters?

What is a cathode heater?

A cathode heater is a heated wire to heat the cathode in a tube. The heater is wrapped around the tube to achieve the required temperature. The wire of a cathode heater is made of a high-resistance metal like nichrome.

What temperatures can cathode heaters reach?

Our cathode heaters are capable of achieving temperatures up to 1400°C – 1600°C. This is very dependent on the wire material that is used.  Our heaters can be made out of various refractory metals which are a proven solution to meets these high requirements.

Why are cathode heaters used in ion thrusters?

Ion thrusters are widely applied in solid fuel propulsion systems that are used to adjust satellite trajectories and propel  spacecrafts through the solar system. An ion thruster operates by ionizing propellant, resulting in positive ions and negative electrons called plasma. The positively charged plasma is generated in the cathodes, typically with a cathode heater wrapped around it to generate the excitation heat needed to start the plasma flow. The mineral insulated heater is very suitable for these kind of applications because of the high-temperature resistance and long durability in vacuum environments.

Read more about Kamet ‘s heating solutions for het Aerospace industry.