Negative ion source as a complex system: insights from the network theory

Negative ion sources constitutes a remarkable complex system where several processes occur , interplay and complete. Among them the generation and destruction of negative ions and the co-extraction of negative ions and electrons. Magnetic field introduced to filter the electrons and optimize the extraction can generate themselves asymmetries which deteriorate the performance of the source. As a result the sum of these processes require and accurate tuning of the source parameters in order to optimize the extraction of negative ions and avoid or mitigate the co-extraction of electrons. Modern physics and in particular theory of controllability of complex systems seem to offer a powerful tool in order to optimize the source performance. In the present contribution the complex network theory is applied to verify the controllability of a negative ion source NIO1. The controllability conditions are assessed and the target and driver nodes are identified and a first comparison between theoretical predictions and experimental data is discussed.