Reverse battery model for anodic arc discharges near atmospheric pressure
Reverse battery model for anodic arc discharges near atmospheric pressure
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DOI：
10.1088/1361-6463/ab3c71
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
C. Corbella;S. Portal;M. Kundrapu;M. Keidar
中科院分区：
文献类型：
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作者：
C. Corbella;S. Portal;M. Kundrapu;M. Keidar
在这项研究中，宏观电参数的阳极电弧放电与固体碳和钼阳极进行描述的等效电路。提出的一维模型表明，等离子体体积的行为作为一个耗散介质结合自生电压从等离子体鞘。该模型通过拟合电阻器和电池的虚拟电路来测试，以测量代表大气电弧过程（300和500 Torr He）的电压-电流（V-I）特性，从而识别与电弧技术相关的两种现象。首先，稳定的直流电弧实验表明，一个最小的电弧电压（V0 = 20-30 V）或阈值电压是必要的，以保持等离子体arc. Second，我们证明，脉冲电弧放电激励的矩形电流波形（1-5 Hz），从来没有熄灭，但保持点燃在脉冲的非活动时间，只要上述阈值电压被维持。总之，具有固体电极的大气阳极电弧放电消耗电功率作为与外部电压供应相对的电压源以及考虑等离子体阻抗的电阻器。这种方法使我们能够估计基本的等离子体参数，从简单的电气诊断，以及预测如何在阳极电弧内的功耗分布，并了解由周期性信号激发的电弧等离子体的动态。
In this study, the macroscopic electrical parameters of anodic arc discharges performed with solid carbon and molybdenum anodes are described in terms of an equivalent circuit. The proposed 1D model shows that the plasma volume behaves as a dissipative medium combined with self-generated voltage from the plasma sheaths. This model is tested by fitting virtual circuits of resistors and batteries to the measured voltage–current (V–I) characteristics representative of atmospheric arc processes (300 and 500 Torr He), resulting in the identification of two phenomena relevant for arc technology. First, steady DC arc experiments show that a minimal arc voltage (V0 ≈ 20–30 V) or threshold voltage is necessary to keep the plasma arc on. Second, we prove that pulsed arc discharges excited with rectangular current waveforms (1–5 Hz) are never extinguished but remain ignited during the inactive time of the pulse as long as the aforementioned threshold voltage is maintained. In summary, an atmospheric anodic arc discharge with solid electrodes consumes electrical power as a voltage source opposed to the external voltage supply together with a resistor that accounts for the plasma impedance. This approach permits us to estimate basic plasma parameters from simple electrical diagnostics, as well as to predict how power consumption is distributed within an anodic arc and to understand dynamics of arc plasmas excited by periodic signals.