On the flute instability in a Q-machine

The influence of the cathodes of a double-ended Q-machine on a flute instability of the Rayleigh-Taylor type is investigated for a low β plasma column. It is shown that flute modes are strongly affected by the end plate conditions and by the machine length. The occurrence of ion-rich sheaths is a necessary condition for the validity of the dispersion relation of the unbounded case. The range of values of the column length for the existence of a given flute mode is determined.