Study of Faraday cup designs suiting multiple electric propulsion systems – 23 June 2022

Authors: V.Hugonnaud, D.Krejci, S.Mazouffre, S.Zoehrer, E.Bosch Borràs and N.Wallace

Published On: June 19-23, 2022

Event: 37th International Electric Propulsion Conference – Massachusetts Institute of Technology, Cambridge, MA USA, IEPC-2022-164


Several designs of a Faraday Cup (FC) were assessed to understand their impact on the measurement of the ion current in the ion beam of two different low power electric thrusters, namely: a Field emission electric propulsion and a radiofrequency ion engine. These two thrusters are of interest because they are among the most popular in the space propulsion market. Moreover, on a more technical and scientific viewpoint, they allow the investigation of a wide range of conditions as they operate with different propellants (indium and xenon), different current densities and with ion energies from several hundreds to thousands of volts. Study outcomes show that for both thrusters the length of the FC is a key design parameter to passively mitigate overestimation of the measured ion current. Indeed, as opposed to other classical electric propulsion systems, such as Hall thrusters, measurements in the ion beam of FEEP and RF thrusters are strongly dependent on the ion-induced electron emission yield mostly due to the ion energy range (keV) at stake. The use of ion collectors made of non-standard materials with complex structure is also of great help to reduce the ion-induced electron yield. Indeed, for aluminium the yield decreases in average by 11±3% for the RIT and 60±8.4% for the FEEP depending on the collector structure dimensions. Finally, the true ion current can be properly retrieved with the right FC architecture where  secondary electron emission effects are completely counter balanced.

Thank you for your interest in ENPULSION’s products and services!

As a global market leader in electric propulsion for nano- and microsatellites, we offer you a broad range of fully integrated electric propulsion systems, as well as simulator and emulator products, and support and services to guide you from first conceptual steps to spacecraft design, integration, launch-preparation, as well as commissioning and operations, all the way to end-of life de-orbiting of your spacecraft – our expert teams are always at your side.

Exclusive ENPULSION data-room

If you are interested to gain access to the next layer of technical information and in-depth knowledge of our products and technology, please contact us. In the ENPULSION data-room you can find product-specific user manuals, in-depth technical guides and applicable documents, containing valuable information on handling and shipping requirements, as well as everything you need to know to get the best performance and utility out of your ENPULSION products.

    Thruster Framework Download

    Would you like to receive additional information? Then please fill in this form and we will get back to you with more details.