Identification of ion cyclotron drift instability

Spontaneously excited oscillations with frequencies of the order of the ion cyclotron frequency and its harmonics in a TP-D type argon plasma confined by a weak magnetic field have been identified as an ion cyclotron drift instability due to the radial gradient of the density. These waves propagate mainly parallel to the electron diamagnetic drift and have an azimuthal mode number m = 1. Experimental characteristics of waves indicate a good agreement with the theoretical aspects of the ion cyclotron drift instability, taking into account the radial gradient of electron temperature and collisional effects. (author)