Cooperative microexcitations in 2+1D chain-bundle dusty plasma liquids

Abstract

Through direct visualization at the discrete level, the microexcitations in cold 2 + 1D dusty plasma liquids formed by negatively charged dusts suspended in low pressure gaseous discharges were experimentally investigated, in which the downward ion flow wake field induces strong vertical coupling and chain bundle structure. It is found that the horizontal structure and motion are similar to those of the two-dimensional liquid. Different types of basic cooperative chain excitations: straight vertical chains with small amplitude jittering, chain tilting-restraightening, bundle twisting-restraightening, and chain breaking-reconnection, are observed. The region with good ͑poor͒ horizontal structural order prefers the straight ͑tilted or broken͒ chains with little ͑large͒ titling and tilting rate.

Interaction of two-dimensional plasma crystals with upstream charged particles

“…This phenomenon is well known as the ion-wake effect causing, e.g. the particles to pair [2,[25][26][27][28]. The particle-lattice repulsion resulting from the Yukawa repulsive force at the apex of the type II cone is a well-established effect [13][14][15][16][17].…”

“…Positive ions that concentrate locally below the extra particle exert an attractive force on the negatively charged particles of the lattice layer. This phenomenon is well known as the ion-wake effect causing, e.g., the particles to pair [2,[25][26][27][28]. The particle-lattice repulsion resulting from the Yukawa repulsive force at the apex of the type-II cone is a well-established effect [13][14][15][16][17].…”

Bacterial turbulence reduction by passive magnetic particle chains

“…Figure 5(b) shows the spatial pair correlation function g(r), which measures the probability of finding a pair of particles with separation r in the xy plane. Unlike the pronounced first peak of g(r) in the cold liquid state [39][40][41], the flat distribution of g(r) beyond the critical distance r c = 14 μm and the fast descending of g(r) below r c for run II indicate that the interchain repulsive coupling effect can only extend to r c . Our estimation shows that the interchain repulsive force for a chain containing 25 particles at r = r c /2 is only about 40% of the single bacterial driving force (0.36 pN) [11] or the drag force on a single particle from a flow at V = 38 μm/s.…”

Agglomeration processes sustained by dust density waves in Ar/C2H2 plasma: From C2H2 injection to the formation of an organized structure

“…Several observations support this assumption, e.g., several dust molecules were observed to rotate around their vertical axis and occasionally two of them exchanged their respective positions. Such behavior has already been observed e.g., in the work of Io et al 25 …”

“…Such chains can be considered as the elementary structure composing dust gathering. 25 It has been designated as "dust molecule." 26 This vertical alignment can be explained by an ion focusing effect behind the dust particles when immersed in a plasma sheath 27 which leads to the formation of an ion wake.…”