Time-resolved measurement of plasma parameters in the far-field plume of a low-power Hall effect thruster
Time-resolved measurement of plasma parameters in the far-field plume of a low-power Hall effect thruster
复制标题
低功率霍尔效应推进器远场羽流中等离子体参数的时间分辨测量
DOI：
10.1088/0963-0252/21/5/055020
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
S. Mazouffre
中科院分区：
文献类型：
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作者：
K. Dannenmayer;P. Kudrna;M. Tichý;S. Mazouffre
利用静电探针对小功率永磁霍尔效应推力器的远场羽流进行了时间分辨测量。这些测量是必要的，以便考虑放电的非稳态行为。等离子体电位用圆柱形朗缪尔探针和一个充分加热的发射探针测量，电子温度和密度用圆柱形朗缪尔探针测量。通过对阴极附近的浮动电极施加正弦调制，以保证所有测量的可重复条件，将推进器保持在周期性准谐波振荡状态。放电电流的调制深度不超过约10%。为了实现同步，调制的频率必须接近观察到的现象的固有频率。这取决于选择放电电流还是等离子体电势作为基准而不同。测量结果表明，电子密度的波动跟随放电电流的波动。等离子体电势和电子温度的时间演化是相似的。放电的时间平均特性几乎不受调制的影响。用这两种不同的探针测量等离子体电位是一致的。所观察到的现象是相似的，作为推进剂气体使用的氘和氪。
Time-resolved measurements using electrostatic probes are performed in the far-field plume of a low-power permanent magnet Hall effect thruster. These measurements are necessary in order to account for the non-stationary behavior of the discharge. The plasma potential is measured by means of a cylindrical Langmuir and a sufficiently heated emissive probe, the electron temperature and density are measured with a cylindrical Langmuir probe. The thruster is maintained in a periodic quasi-harmonic oscillation regime by applying a sinusoidal modulation to a floating electrode in the vicinity of the cathode in order to guarantee repeatable conditions for all measurements. The modulation depth of the discharge current does not exceed approximately 10%. In order to achieve synchronism, the frequency of the modulation has to be close to the natural frequency of the observed phenomena. It is different depending on whether the discharge current or the plasma potential is selected as a reference. The measurements show that the fluctuations of the electron density follow the discharge current fluctuations. The time evolution of the plasma potential and the electron temperature is similar. The time-averaged properties of the discharge remain almost uninfluenced by the modulation. Measurements of the plasma potential with the two different probes are in good agreement. The observed phenomena are similar for Xe and Kr used as propellant gases.