An atmospheric pressure self-pulsing micro thin-cathode discharge
An atmospheric pressure self-pulsing micro thin-cathode discharge
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DOI：
10.1088/0022-3727/44/12/125204
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发表时间：
2011-03
期刊：
影响因子：
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通讯作者：
B. Du;S. Mohr;D. Luggenhölscher;U. Czarnetzki
中科院分区：
文献类型：
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作者：
B. Du;S. Mohr;D. Luggenhölscher;U. Czarnetzki
微细阴极放电(μ-TCD)是一种改进的微中空阴极放电，其阳极比MHCD中的阳极厚得多，从而可以在大气压下稳定运行。μ热释光探测器在不同的气压下通过直流电压在氩气中工作。在大气压下，μTCD以自脉冲模式工作，电流峰值持续几纳秒，电流密度高达105A cm−2，由存储在放电设备电容中的电荷提供。用ICCD摄像机观察等离子体发射。电压-电流特性和ICCD图像都表明，这种自脉冲是由于火花放电的周期性点火造成的。电子密度的测量是通过H-β谱线与1%氢的混合斯塔克加宽。在周期性火花放电模式下，电子密度约为1016 cm−3。直接测量这类放电中的放电电流是不可能的，因为它是由放电装置的固有电容驱动的。因此，建立了包含杂散电容的电学模型。模拟结果与实际测量的电流和电压吻合较好。
A micro thin-cathode discharge (μTCD) is a modified micro hollow-cathode discharge (MHCD) where the anode is much thicker than the one in a MHCD, which allows a stable operation at atmospheric pressure. The μTCD was operated at different pressures in argon by a dc voltage. At atmospheric pressure, the μTCD operates in a self-pulsing mode with current peaks with a duration of a few nanoseconds and a current density up to 105 A cm−2, supplied by the charge stored in the capacitance of the discharge device. The plasma emission was observed by an ICCD camera. Both, the voltage–current characteristic and the ICCD image indicate that this self-pulsing is due to a periodic ignition of a spark discharge. The electron density was measured by Stark broadening of the Hβ-line with an admixture of 1% hydrogen. In the periodic spark mode the electron density is of the order of 1016 cm−3. The direct measurement of the discharge current in these kinds of discharges is not possible, since it is driven by the inherent capacitance of the discharge device. Therefore, an electrical model including stray capacitances is set up. The modelled results agree very well with the measured currents and voltages.