Space charge limiting current in a coaxial transmission line

Author(s):  
G.V. Sotnikov ◽  
T.Yu. Yatsenko
Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 342
Author(s):  
Makhamet Urtenov ◽  
Vitaly Gudza ◽  
Natalia Chubyr ◽  
Inna Shkorkina

In electromembrane systems, the theoretical study of salt ion transport usually uses mathematical models of salt ion transport in the depleted diffusion layer of ion-exchange membranes. This study uses a one-dimensional mathematical model of salt ion transport in a cross-section of a desalination channel formed by anion-exchange and cation-exchange membranes, taking into account an effect of a dissociation/recombination reaction of water molecules. The reaction on the one hand leads to an overlimiting mass transfer due to the effect of exaltation of the limiting current. On the other hand, an appearance of new electric charge carriers (hydrogen and hydroxyl ions) can reduce the space charge that occurs in membranes and suppress an electroconvective mechanism of overlimiting transport. Thus, there is a problem of studying these phenomena together, taking into account their mutual influence, and this article is devoted to the solution of this problem. Theoretically, using a method of mathematical modeling and numerical research, main regularities are established; in particular, it is shown that the dissociation/recombination reaction of water molecules does not lead to the destruction of the double electric layer at the membranes, but also creates a new double electric layer in the middle of the desalination channel. Thus, the space charge and the dissociation/recombination reaction significantly affect each other and simultaneously the transport of salt ions.


1998 ◽  
Vol 26 (3) ◽  
pp. 854-859 ◽  
Author(s):  
T.A. Spencer ◽  
K.J. Hendricks ◽  
J.W. Luginsland ◽  
M.D. Stump

Plasma ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 222-228 ◽  
Author(s):  
Mikhail Fuks ◽  
Dmitrii Andreev ◽  
Artem Kuskov ◽  
Edl Schamiloglu

In our earlier work, we showed that a low-energy state of an electron beam exists in a nonuniform channel between two virtual cathodes in a magnetron with diffraction output, which consists of three uniform sections with increasing radius. A uniform axial magnetic field fills the interaction space. This led to magnetron operation with >90% efficiency when combined with a magnetic mirror field at the output end. In this present paper, we show that a low-energy state of an electron beam can be realized in a uniform channel in which an increasing magnetic field is used in order to create a magnetic mirror at the output end. We consider two cases, one where the injected beam current slightly exceeds the space-charge-limiting current and the other where the injected beam current greatly exceeds the space-charge-limiting current. On the time scale of relevance to planned experiments (∼30 ns), when the injected current slightly exceeds the space-charge-limiting current a stationary virtual cathode forms and when the injected current greatly exceeds the space-charge-limiting current the virtual cathode oscillates back and forth.


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