7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Research on Transport Characteristics of Vacuum Arc Plasma with Super Large
Length-to-Diameter Ratio
Shuangwei Zhao1, Xiaolong Huang1, Shenli Jia1,2
1College of Electrical Engineering Sichuan University
2
State Key Laboratory of Electrical Insulation and Power Equipment , Xi’an Jiaotong University
e-mail (speaker):13258103492@163.com

Vacuum arc is widely used in material surface treatment,
metal smelting, aircraft propulsion device, medium andhigh voltage vacuum interrupter, etc. The development
intensity of high voltage vacuum interrupter depends on
the research of high current vacuum arc plasma
characteristics. Vacuum arc plasmas are composed ofvarious particles, including electrons, atoms, and ions ofdifferent charge states. The metal in a localized cathodesurface area is continuously melted and evaporated tomaintain the vacuum arc. The high-current vacuum arc iscontracted on the anode side, and the longitudinalmagnetic field is mostly used to control the high-current
vacuum arc to suppress its contraction. There are complex
physical processes in the vacuum arc, and it is difficult tofully reflect the dynamic change process of the plasma
parameters inside the vacuum arc only throughexperimental research. Simulation research is an effectivemeans for in-depth research on high-current vacuum
[1]
arcs.
The development of vacuum interrupters to higher voltage
levels requires higher insulation levels. The active
threshold current of the anode of the interrupter increases
with the diameter of the anode and decreases with theincrease of the contact gap. Therefore, the contact
diameter of the interrupter and the maximum contact gap
will be large. The characteristics of vacuum arc plasma

with super large length-to-diameter ratiot are different
from those of small contact opening distance (10mm) and[2][3]small contact diameter (49mm) in previous studies.
Inorder to reveal the ultra-large aspect ratio vacuum arc
plasma transport characteristics, we established a Twodimensional magnetohydrodynamic model of a vacuumarc with super large length-to-diameter ratiot.
We explored the transport characteristics of the vacuumarc plasma when the arc extinguishing chamber (contactopening distance 70mm, contact diameter 150mm)interrupted 71kA power frequency current, as shown in
Figure 1, the vacuum arc plasma under the longitudinalmagnetic field Body characteristics, as shown in Figure 2.
The vacuum arc with a large diameter and large opening
distance presents a shrinking state, the control effect of theaxial magnetic field in the arc area is weakened, and thevacuum arc current density shrinks to both sides under theaxial magnetic field.
References[1] S.L Jia et al, J. Phys. D: Appl. Phys. 47 403001 (2014)[2] L.H Zhao et al, J. Phys. D: Appl. Phys. 54 105501(2021)[3] D.L Shmelev et al, IEEE T PLASMA SCI. 43(8), 226
1-2266 (2015)(a)bz=0(a)bz=300mTFigure1. Arc axial plasma pressure, plasma density, electron
temperature , ion temperature distribution . The electrode opening
distance and arc radius correspond to the vertical and horizontal coordinatesin the figure. Anode on top, cathode on bottom

Figure2. Axial current density
distribution. The electrode opening
distance and arc radius correspond tothe vertical and horizontal coordinatesin the figure. Anode on top, cathode on
bottom