Vertically aligned dust particles under the influence of crossed electric and magnetic fields in the sheath of a radio frequency discharge

Abstract

We present experiments on two dust particles with a size of a few microns that are levitated in the sheath region of an rf discharge in the presence of an external magnetic field transverse to the sheath electric field. The two particles are vertically aligned due to the ion focusing effect. First, it is observed that the magnetic field causes a displacement of the dust particles either in the E→×B→- or in the opposite direction. Second, at a sufficiently large neutral gas pressure, the vertical alignment breaks up when the magnetic field strength is increased. The occurrence of this dissociation is described by the horizontal force balance on the two particles.

Transverse forces on dust particles in a magnetized sheath with crossed electric and magnetic fields

“…Further, the influence on vertically aligned dust particles is studied. It is found that the ion wake that is responsible for the vertical alignment is destroyed and that the vertical alignment is easily broken by the magnetic field [2].…”

Dusty (complex) plasmas—routes towards magnetized and polydisperse systems

“…parallel to the electrodes. There, one finds a quite complex reaction of the dust particles even at relatively small fields [214][215][216][217]. Vertically the dust is trapped by the force balance of electric field force and gravity Q d E z =m d g, as discussed above.…”

“…At further increased field the particles start to move back to the original position along the   E B direction, see figure 14(b). The sideways motion of the dust strongly depends on the particle size as well as the gas pressure [215][216][217].…”

“…Also the vertical interaction between dust particles trapped in the sheath is modified by the presence of a horizontal magnetic field [216]. An example is shown in figure 14(c) where a pair of vertically aligned particles is influenced by the horizontal magnetic field.…”

Dynamics of dust particles in the glow discharge stratum in crossed E × B field

“…A similar situation with dust particles in the magnetic field suspended near the electrode layer of the RF discharge also moved in the direction opposite to the E × B drift. [24][25][26] In the works of Barnat, [27] the properties of RF discharge in a perpendicular magnetic field were investigated. It should also mention the theoretical study [28][29][30][31][32] of the influence of weak transverse/longitudinal magnetic fields on the dynamics of dust structures.…”