Effects of low-frequency instability on the Hall conductivity in plasma: Applications to astrophysics and space physics

Nonlinear wavy phenomena into plasma: some cases of stabilization and control of chaotic behaviors

“…The external driving signal, which was used, is an electrical one with the ability to propagate into the plasma emitted from a Langmuir probe. In a previous research [21], the drift wave synchronization has been achieved and a very interesting influence on the Hall conductivity has been revealed. However, in this paper, we study only the driving signal frequency shifted toward the fundamental of the drift wave.…”

The big contradiction between the perturbation theory and the chaotic state. A detailed mathematical analysis indicates when the plasma is stable or unstable

“…8 These two different plasma configurations have been studied extensively by the research team of the Plasma Laboratory of 'Demokritos'. [9][10][11][12] The study of both the plasma's stable and unstable state is easier using drift waves since they have been studied extensively in the past. Here a brief overview of these low-frequency drift waves is given.…”

Further research of the collisional instability. An extensive study of growth and a notable influence of the boundaries

“…N. D'Angelo and N. Rynn have observed [1,2] drift waves for the first time (1961), and since then the drift instabilities have been researched systematically in linear devices with different plasma parameter values, for example, collisionless plasma [6], collisional plasma [7][8][9], fully ionized [4] and weakly ionized [7,10]. Many experiments for drift wave study have been carried out in Q-machine device magnetized plasma, when β is very small [10][11][12] (β is the ratio of plasma pressure to magnetic pressure, and is compared with the ratio of electron to ion mass m e /m i ). When β is small, the drift instabilities are electrostatic, and as β takes higher values, the parallel electron response becomes Alfvenic [8].…”

“…At plasma laboratory of NCSR 'Demokritos' a quiescent rf argon plasma in Q-machine, with cylindrical symmetry is being produced [10][11][12]. The production way, with the microwave antenna located at the axis of the cylindrical cavity where the discharge occurs, and the rf generator (magnetron), operating at 2.45 GHz, gives weakly ionized plasma (plasma density ≈ 10 16 m −3 ), which can easily be sustained with 20-120 W of microwave power.…”

“…In a previous paper [10], we presented the waves of 20 kHz region, which are caused by rf-field gradients. In another paper [11], the effects of this instability on Hall plasma conductivity due to electron trapping were examined. In the last paper [12], I present experimental results concerning the instability of the 70 kHz region, which maximizes in a cylindrical cell of average radius r ∼ = 2.5 cm, with standard spectrum, unique behaviour and could be classified as a drift wave due to the electron collisions with neutral atoms and molecules [16].…”