Quiescent plasma experiments: an add-on

In the classical literature of plasma physics, one cannot miss the references of Q-machines. It was such a powerful experimental device in which the very early basic plasma experiments were conducted and the results from those went into all plasma physics text-books. In those experiments, a highly ionized plasma produced by contact or resonance ionization of alkali atoms (mostly cesium) on hot tungsten surfaces was confined in an axial magnetic field. This collision-less plasma was expected to be quiescent, because the temperature of both the species (ions and electrons) would be same as the temperature of the plate (∼ 0.2 eV). But due to the inherent experimental set ups, many fluctuations were present, which were detected and were satisfactorily explained too. In this talk, the highlights of these Q-machine experiments conducted worldwide will be revisited and a possible add-on would be discussed. (author)