60Change of the Potential Relaxation Instability in a plasma containing heavy C ions

Publisher Summary The fullerene C 60 has a very large cross section for electron attachment over a wide range of electron energies, from thermal energies up to 10 eV. This feature can be utilized to produce a plasma containing C - 60 ions. This chapter presents the influence of the C - 60 ions on the potential relaxation instability (PRI). This instability is a large amplitude relaxation type oscillation of the plasma potential as well as of the plasma density. PRI-like oscillations can be observed in any low density current carrying bounded plasma system. In a Q-machine the PRI can be excited by biasing the cold end plate (CP) with a positive voltage. Since the driving mechanism of the PRI is the loss of the negative charge carriers by the positive voltage of the CP and the inertia of the positive charge carriers, the PRI is strongly influenced by the C - 60 ions, since their mobility is much lower than the mobility of the electrons.