Self-organisation at the origin of spatiotemporal structures in a Q-machine

Spatiotemporal structures appear in a Q-machine after proceeding a series of key processes whose presence is evidenced by non-linear variations of the electrical conductivity of the plasma column. Knowing that such a behaviour emphasises the presence of self-organization we propose a new phenomenological description of the potential relaxation instability and, implicitly, of the electrostatic ion-cyclotron instability. (author)