Investigation of Efficient Designs of Hollow Cathodes

Paper number

IAC-06-C4.P.4.07

Author

Ms. Janice Hendry, University of Southampton, United Kingdom

Year

2006

Abstract

Hollow cathodes can be used for several applications, the main two being electric propulsion and charge mitigation. This investigation looks mainly at the charge mitigation side but should be equally applicable for ion thrusters. 

This paper will detail the redesign of the internal geometry of hollow cathodes as an attempt to change flow dynamics of the plasma. This will hopefully lead to improved performance and increased lifetime. Three designs will be investigated. The first geometry variation consists of changing the shape of the internal part of the orifice and reducing blunt surfaces within the hollow cathode. The second design will induce vortices by forcing the plasma around a ‘twist’. This twist will be made of titanium, and therefore doubles as gas purification. The final design will combine the first two, to see how they work in conjunction with each other. Ideally, the three designs will be tested independently to see how they each alter the flow dynamics and to see if one design has an advantage over the other.

Argon gas will be used to initially test the designs, and if funding is available, the best design will be further tested using xenon. The hollow cathode will be an altered T6 made by QinetiQ, and will have a standard insert and enclosed keeper. The planned results will contain the current produced by the hollow cathode, the temperature they run at relative to each other using a pyrometer and possibly the thrust exerted. It is planned that each design will run in spot mode for approximately 50 hours. If time and resources permit, the best design will be tested for a further 50 hours using either xenon or argon. It is hope that our results will be relevant for both charge mitigation applications as well as for electric propulsion and ion thrusters, ideally leading to an improved design.

This paper will briefly detail how hollow cathodes are used for both charge mitigation and as the ion source for electric propulsion and as a charge neutraliser. It will then demonstrate our design process from initial ideas to final designs and why specific designs were chosen over others. It will also detail results of our testing, which should be completed by April 2006.

Abstract document

IAC-06-C4.P.4.07.pdf

Manuscript document

IAC-06-C4.P.4.07.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.