The relaxation of strongly anisotropic magnetized plasmas by electromagnetic ion-cyclotron instability

A computer simulation is used to investigate the non-linear behaviour of the electromagnetic ion cyclotron instability in a homogeneous plasma. The results indicate (i) a fast build up of left-hand (proton-like) polarized electromagnetic waves: the peak-value energy is about 230 times larger than the initial one and represents about 10% of the total energy in the system; (ii) a significant relaxation (isothermalisation) of the initial thermal anisotropy value of 100 to a minimum value of about '3' (at peak field value); (iii) the establishment of a quasi-equilibrium state (from the collective point of view).