Generation of high-power chaos - a proposed scenario

Summary form only given. In the course of the last decade, interest in the generation of high power chaos has grown substantially. This development was largely enhanced by the range of possible applications which among others include coding, ultra-wide-band (UWB) spread spectrum communication systems as well as detection and radar. Also a new field of research has opened up with the realisation that the interaction between E-M radiation and live tissue should be investigated more closely, either using high power microwave pulses, low power chaos for dosimetry purposes and THz radiation for diagnosis of some malignant growth. So far various methods have been tried in search for suitable sources of high-power chaos. For example 30 ns high-power pulses have been obtained by feeding an amplitron with anharmonic signals. Similarly chaotic oscillations have been generated by hard driving a relativistic BWO, initial simulation results being obtained using MAGIC2D. Others used a smooth anode magnetron to achieve somewhat similar results; also the effect of a time-delayed feedback in both klystrons and TWTs on generating chaos has been investigated. In our own research group we investigated the generation of chaos using plasma filled diodes. As a result of all the above research effort we have decided that a more systematic approach to the generation of high-power chaos would not be out of place. In our contribution we propose to discuss what we consider to be the essential requirements for the generation of high-power chaos. High power, of whatever kind, can only be achieved using high voltages and currents; this immediately brings us into the realm of relativistic kinematics, since in practice we would be operating in the region of 500 kV and above. It would appear that the magnetic field invariably plays a crucial role in the interaction process. We are going to show, using the simplest possible means, why it should be so, especially as far as the energy volume density i- the interaction space is concerned. We have shown already that chaos can be generated in a plasma-filled diode even without the presence of a magnetic field; therefore an addition of plasma is likely to facilitate the development of chaos via the usual cascade of bifurcations. These are the three points which we propose to discuss more fully as part of our presentation