Investigations about the Influence of the External Circuit Elements on the Propagation of Ionization Waves in the Positive Column of a Neon Glow Discharge

Our investigations have been motivated by former works of Michel and Achterberg [1]. They described the important influence of the external circuit elements and connected therewith the mechanism of feedback (Barkhausen k · v ≧ 1). The properties of external and self-excited moving striations (threshold current, fundamental frequency) are strongly influenced by the feedback. This paper demonstrates the differences occuring either a voltage or a current source in the external circuit is used in order to perturb the discharge and to realize different degrees of feedback by changing the external resistor R_ext. of the discharge. It is shown the impact on the fields of existence of self excited striations in a non driven discharge. Furthermore our investigations yield differences in the width of Arnol'd tongues [2] of periods one and two in the perturbed discharge depending on a varied degree of feedback. Last not least its influence on the behaviour of quasiperiodic and chaotic states is demonstrated. The investigations permit first information concerning the sensivitity of one parameter variation (feedback controll by external resistor) which might be used e.g. for a stabilization of unstable periodic orbits (controlling chaos).