Three-fluid simulation of a cathode spot jet in vacuum arc discharge with a metal deuteride cathode

Sun, Qibin; Yang, Weiping; Zhou, Qianhong

doi:10.1088/1361-6463/ab850e

Cited by 4 publications

(16 citation statements)

References 36 publications

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“…The physical model used in this paper had been introduced before [22]. As shown in figure 1, the plasma in the vacuum arc is generated by numerous cathode spots on the cathode surface.…”

Section: The Numerical Modelmentioning

confidence: 99%

“…Therefore, the Lorentz forces can be ignored compared to the pressure gradients in this paper. (c) The three-component plasma in the vacuum (Zr ions, D ions, and electrons) is described using the three-fluid approximation [22,23]. The momentum and energy transfer by collisions is taken into account between different species while pressure gradient is considered between the same species.…”

Section: The Basic Assumptionsmentioning

confidence: 99%

“…The first term on the right-hand side of equations ( 3) and (4) represents the pressure gradient of ions, the second term represents the corresponding electron pressure gradient, the third term represents the viscous force, the fourth and fifth term represents the electron-ion collision, and the last term represents the ion-ion collision (Zr-D). The equations ( 3) and ( 4) are derived by the generalized Ohm's law, and detailed derivation process can be seen in previous paper [22].…”

Section: Conservation Equationsmentioning

confidence: 99%

“…To elucidate physical mechanism of the separation phenomenon, some numerical simulations have been developed [9,[20][21][22][23][24]. Shmelev et al [20,21] studied the mixing and interaction of multi-cathode spot jets through the hybrid modeling.…”

Section: Introductionmentioning

confidence: 99%

“…This severely restricts the further application of multicomponent vacuum arc. In our former work [22], a 2D three-fluid model had been developed to study the physical mechanism of individual cathode spot jet in metal deuteride cathode vacuum arc. However, the mixing effect between multi-cathode spot jets were not considered.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Study of ion separation mechanism in the multi-component vacuum arc discharge

Sun¹,

Zhou²,

Zhang³

et al. 2022

Plasma Sources Sci. Technol.

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The separation phenomenon of light and heavy ions was widely observed experimentally in the vacuum arc discharge with multi-component composite cathode. In this work, a two-dimensional axisymmetric multi-fluid model is used to study the separation mechanism in the multi-component composite cathode vacuum arc. The multi-component vacuum arcs are simulated as a whole which includes separate cathode spot jets, the mixing region, and common arc column. The results show that the plasma jets originated from the separate cathode spot mix together to form a common arc column after a certain distance from the cathode. Due to the rapid increase of ion temperature dozens of times in mixing region of cathode spot jet, the effect of pressure gradient becomes far greater than that of the collisions between light and heavy ions. This leads to a shift in the predominant ion motion mechanism from ion-ion collision (single cathode spot jet region) to pressure expansion (the mixing region). Finally, the light ions gain higher velocities under pressure expansion. In addition, the effect of thermal conductivity and viscosity leads to the wider high temperature regions for light ions, thus making a wider distribution of corresponding ion flux. The numerical results are qualitatively consistent with the experimental results. This paper provides an insight into ion separation mechanism in the multi-component vacuum arc.

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“…The physical model used in this paper had been introduced before [22]. As shown in figure 1, the plasma in the vacuum arc is generated by numerous cathode spots on the cathode surface.…”

Section: The Numerical Modelmentioning

confidence: 99%

Section: The Basic Assumptionsmentioning

confidence: 99%

Section: Conservation Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Study of ion separation mechanism in the multi-component vacuum arc discharge

Sun¹,

Zhou²,

Zhang³

et al. 2022

Plasma Sources Sci. Technol.

Self Cite

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Study on the characteristics of different species in the vacuum arc devices with deuteride cathode

et al. 2023

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To study the physical mechanism of the separation between heavy and light species in the vacuum arc devices with deuteride cathodes, a three-fluid model based on magnetohydrodynamic (MHD) theory is established. In the model, different kinds of species are considered to be different kinds of fluids, and their physical parameters are calculated separately. Moreover, the distribution of arc current is calculated by the generalized Ohm's law, and the ionization and recombination of species are taken into account. In the paper, the two cases where the cathode is Zr or ZrD0.67 are simulated, respectively. The results show that in the case of ZrD0.67 cathode, the separation of light and heavy species is remarkable. Because of D's lighter mass and lower mass-to-charge ratio, the distribution of it is more uniform. In addition, the differences between species also lead to large differences in other physical characteristics, such as ion velocity, ion temperature, and so on. Notably, the desorption and ionization of deuterium lead to a decrease in plasma temperature. The self-generated magnetic field of the arc has an inhibitory effect on the expansion of each species, and it is more obvious for ions with lower mass-to-charge ratio. The simulation results are consistent with the experimental results. The theoretical analysis can provide theoretical guidance for the improvement of vacuum arc devices with composite or gas-saturated cathodes.

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Effect of ion collision on separation between light and heavy ions in multi-component vacuum arc

Sun,

Zhou,

Yang

et al. 2023

Plasma Sources Sci. Technol.

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In multi-component vacuum arc discharge, light ions and heavy ions usually have different spatial distributions of density and velocity. Previous research has suggested that the difference in spatial distribution of light and heavy ions is due to the mixing effect of cathode spot jet. However, in this work, the ion collision is found to be an important factor leading to the separation of light and heavy ions. In this paper, multi-fluid model is used to study the effect of ion collisions on separation mechanism in multi-component vacuum arc. The simulation results show that, during the jet mixing process, the collisions between different ions will reduce the velocity of light ions, and greatly increase the density and temperature. As a result, the pressure expansion of light ions is significantly enhanced. In addition, the collision between different ions will also increase the size of jet mixing region for light ions, which makes the plasma jet of light ions mixing more fully. These effects make their isotropic expansion dominant, and the ion density at the center is not much different from that at the edge. However for heavy ions, the collision between different ions has little influence on their movement. The pressure is far less than the inertia force, so the density of heavy ion mainly distributes along the convection direction, and the center is greater than the edge. This is the main separation mechanism of ion angular flux. It is also found there are three main factors leading to the separation of light and heavy ions: ion mass, ion density and ion temperature. The separation effect can be enhanced by increasing ion temperature, decreasing ion density and selecting electrode components with significant differences in elemental mass. This paper provides an insight into the mechanism of ion separation in multi-component vacuum arc.

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Three-fluid simulation of a cathode spot jet in vacuum arc discharge with a metal deuteride cathode

Cited by 4 publications

References 36 publications

Study of ion separation mechanism in the multi-component vacuum arc discharge

Study of ion separation mechanism in the multi-component vacuum arc discharge

Study on the characteristics of different species in the vacuum arc devices with deuteride cathode

Effect of ion collision on separation between light and heavy ions in multi-component vacuum arc

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