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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Principle of Inertial Electrostatic Confinement (IEC)

IEC basic concept
Figure. 1  Description of IEC principle

The working principle of IEC is shown in Figure 1. The simplest setup of an IEC device consists of two spherical, concentric electrodes, the outer being the anode and the inner being the cathode. Having an electric potential difference between the inner and outer grids, a glow discharge ignites at respectively low pressure between the electrodes creating charge carriers. The ions get accelerated toward the negatively biased inner grid; while electrons are directed to the grounded outer grid. Ion travel through the inner grid to another side of anode and pushes back to the cathode by the electric field. It keeps flying back and forth and gains kinetic energy if there is no collision occurred with neutrals or grids. If the kinetic energy of ion is sufficient, fusion relevant processes might occur in ion-ion or ion-neutral collision in IEC device. On the other hand, the charge exchange happened when ion-neutral collision occurs, which results in the production of fast neutrals and slow ions

The spherical electric potential contributed from grids drives ions to the core region which causes the accumulation of the positive potential well inside the cathode grid. This potential well in the core also attracts the electrons emitted from cathode flying to the center. The electrons are trapped in the center of cathode by the electrostatic confinement and form another negative potential again. [8] The potentials caused by both ions and electrons clouds reach the balance with the electrostatic confinement as well as the thermodynamic effect. 

Contact: M.Sc. Yung-An Chan