Basic processes in discharge plasma double layers

Abstract

Experimental results regarding the study of plasma double layers (DLs) by electric and spectral methods in the case of a glow discharge obtained in a chamber of three-electrode geometry are presented. The experimental results prove that the appearance of DLs in active plasmas can be accompanied by quantum processes, such as excitation and ionization.

Equilibrium states of anodic double layers

“…The transition from electron sheath to anode glow has been observed experimentally [6] and was numerically investigated by Conde et al [7]. Anode spots have been observed to have a spherical shape, first called 'fireballs' by Song et al [8], and subsequently by others [9][10][11][12][13][14][15], or a cylindrical shape, first called 'firerods' by An et al [16], and subsequently by others [17,18]. Multiple fireballs have also been observed either as nested concentric spheres, 'multiple concentric double layers,' [19][20][21][22][23][24][25][26], or at multiple distinct locations on the anode surface, 'non concentric multiple double layers' [20,21,23,27,28].…”

“…Anode spots have also been used to confine dust particles [17]. Among the properties of anode spot equilibrium reported are the observation that hysteresis accompanies the onset of an anode spot as measured from a current-voltage characteristic on the electrode where the electrode bias must be greater for onset of the anode spot than is required to maintain it [8,10,11,15]. The critical electrode bias necessary for the onset of the anode spot and its characteristic dimension are inversely proportional to the neutral pressure [8].…”

El Naschie’s structures in the electrodynamics of polarizable media

“…For fields with strength comparable to ðjD z j=e 0 Þðe=4pe 0 a 2 0 Þ % 5:3 Â 10 11 V/m, where a 0 = (h 2 e 0 /pe 2 m) % 5.2 · 10 11 m is the radius of the first Bohr orbit, the Larmor electric pulsation is x Le % 1.41 · 10 14 Hz. Furthermore, for the macroscopic coherent structures of anodic double-layer (DL) type with parameters [17,18]: the diameter of the DL with spherical symmetry, D % 6 · 10 À3 m and the electron potential, V = 16 V, x Le % 0.71 · 10 6 Hz, i.e. of the order of pulsation corresponding to the DL appearance-disappearance process [17,18].…”

“…Furthermore, for the macroscopic coherent structures of anodic double-layer (DL) type with parameters [17,18]: the diameter of the DL with spherical symmetry, D % 6 · 10 À3 m and the electron potential, V = 16 V, x Le % 0.71 · 10 6 Hz, i.e. of the order of pulsation corresponding to the DL appearance-disappearance process [17,18].…”

“…The quantities involved in these equations have the usual signification [17,18]. To solve the system of equations (72a,b) we shall use the finite difference method.…”