Prof. Dr.-Ing.
Stefanos Fasoulas


Prof. Dr.-Ing. Sabine Klinkner

Prof. Dr. rer. nat. Alfred Krabbe

Prof. Fasoulas

Larissa Schunter

Prof. Klinkner

Annegret Möller

Prof. Krabbe

Barbara Klett


Dr. Thomas Wegmann


Institut für Raumfahrtsysteme
Pfaffenwaldring 29
70569 Stuttgart

Tel. +49 711 685-69604
Fax +49 711 685-63596

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History of Inertial Electrostatic Confinement

IEC for fusion

IEC is a device, which has originally been in use in the field of fusion research. The design concept for IEC is to heat up and to confine plasma to fusion conditions by strong electric fields. Research on IEC is being performed since the 1950’s, but intensive studies for applications as neutron source is existing in the USA [1][2][3] and Japan [4][5] since 1990. In addition, a former German firm, NSD Fusion GmbH, even brought relevant neutron sources to the market. This firm is now part of Gradel Sarl, Luxemburg, a firm that continuously cooperates with IRS on the research of IEC.

Development of IEC in IRS

Institute of Space System (IRS) started a project with the purpose to understand the jet extraction from IEC devices as well as to evaluate the applicability for space propulsion systems. Two approaches are implemented: modeling and experiment. For modeling, two analysis models are developed: one of analytical mode is for evaluating the formation and composition of plasma core; the other one is served for simulation of the plasma jet extraction. The first model is to assess all possible losses with respective input power in order to evaluate the compositions in the core region. The second model is served as the preliminary understanding of the thrust performance based on the assumed jet extraction condition from IEC device. The detail model development could be found in the Ref.[9]. In addition, a numerical model based on two solvers, Direct Simulate Monte-Carlo (DSMC) method and Particle-In-Cell (PIC) method, was applied in the research of IEC under support from ESA Ariadna study. [10]

On the other hand, the experiment for evaluation of IEC device is performed in parallel. The investigation of the operation parameters, e.g. electrical properties, propellants, background pressure, for IEC device has been done previously.[11]–[13] In addition, the trajectory of the jet extraction could be controlled by designing the configuration of confinement grids to make an electric field opening. Moreover, the investigation of the composition within the core region has been conducted by using emission spectroscopy. [14] However, the understanding of IEC is still far from enough to realize an IEC thruster yet. Much more efforts and research need to be involved in the development of IEC thruster.


  1. G. H. Miley et al., “Inertial-Electrostatic Confinement Neutron/Proton Source,” in AIP Conference Proceedings, 299, 1994.
  2. Y. Gu and G. H. Miley, “Experimental study of potential structure in a spherical IEC fusion device,” IEEE Transactions on Plasma Science, vol. 28, no. 1, pp. 331–346, 2000.
  3. G. H. Miley and J. Sved, “The IEC star-mode fusion neutron source for NAA - Status and nextstep designs,” Applied Radiation and Isotopes, vol. 53, no. 4–5, pp. 779–783, 2000.
  4. H. Matsuura, T. Takaki, K. Funakoshi, Y. Nakao, and K. Kudo, “Ion distribution function and radial profile of neutron production rate in spherical inertial electrostatic confinement plasmas,” Nuclear Fusion, vol. 40, no. 12, pp. 1951–1954, 2000.
  5. K. Yoshikawa et al., “Measurements of strongly localized potential well profiles in an inertial electrostatic fusion neutron source,” Nuclear Fusion, vol. 41, no. 6, pp. 717–720, 2001.
  6. Y. Chan, “Lecture of Non-conventional Space Propulsion - Inertial Electrostatic Confinement for Space Propulsion,” Lecture slide, 16, Nov., 2015.
  7. Y. Chan, C. Syring, and G. Herdrich, “Development of Inertial Electrostatic Confinement Devices for Space Propulsion in Irs,” in 5th Space Propulsion Conference, Rome, Italy, May 2016.
  8. G. H. Miley and K. S. Murali, Inertial Electrostatic Confinement (IEC) Fusion Fundemental and Application. New York: Springer, 2014.
  9. G. Herdrich, C. Syring, T. Torgau, Y. Chan, and D. Petkow, “An Approach for Thrust and Losses in Inertial Electrostatic Confinement Devices for Electric Propulsion Applications,” in 34th International Electric Propulsion Conference, Kobe, Japan, July 2015.
  10. G. Herdrich, D. Petkow, C. Syring, and M. Pfeiffer, “Kinetic modelling of the jet extraction mechanism in spherical IEC devices,” ESA Advanced Concepts Team, Ariadna study, 12/3201, 2013.
  11. C. Syring and G. Herdrich, “Jet extraction modes of inertial electrostatic confinement devices for electric propulsion applications,” Vacuum, vol. 136, pp. 177–183, 2017.
  12. T. Baur, Pressure and Discharge Characterization of an IEC test setup, Universität Stuttgart, March, 2013.
  13. T. Gebhardt, Scaling and Discharge Characterization of an IEC test setup, Universität Stuttgart, November, 2013.
  14. C. Syring and G. Herdrich, “Emission Spectroscopic Investigations on Inertial Electrostatic Confinement (IEC) for Propulsion Applications,” in 4th Space Propulsion Conference, Colonge, Germany, May 2014.
  15. B. Gäßler, C. Syring, Q. H. Le, G. Herdrich, and S. Fasoulas, “Assembly and Commissioning of an Electrostatic Probe for the plume Characterization of an Arcjet,” in 2016 Space Propulsion Conference, Rome, Italy, May 2016.
  16. G. Herdrich, C. Montag, and Y.-A. Chan, “Research on Charge Evolution and Propagation on an Ablative Pulsed Plasma (APPT) Source,” DFG project, 2017. (under review)

Contact: M.Sc. Yung-An Chan