Atmospheric breakdown delay and ionization rate of repetitive microwave pulses
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摘要: 针对高功率微波在大气传输中可能出现的击穿现象,研究了脉冲序列中首次脉冲击穿延时和后续脉冲击穿延时,研究结果发现首次脉冲击穿延时在脉宽范围内大致均匀分布,后续脉冲击穿延时波动性较小。根据击穿延时数据对电离率进行了分析,指出在重复频率条件下,初始电子密度较高,电子密度分布不适用指数分布,无法用延时数据标准差对电离率进行估计。提出了一种用重复频率脉冲击穿延时数据计算电离率的方法,并将计算结果与仿真结果进行了对比,结果显示,二者有较好的对应关系。Abstract: Aiming at the possible breakdown phenomenon of high power microwave in atmospheric transmission, this paper focuses on the study of the first pulse burst delay and subsequent pulse burst delay in pulse sequences. It is found that the first pulse burst delay is approximately uniformly distributed within the pulse width range, and the subsequent pulse burst delay has a small jitter. The ionization rate is analyzed based on the breakdown delay data, and it is pointed out that under the repeated frequency condition, the initial electron density is high, and the electron density distribution is not suitable for exponential distribution, which makes it impossible to estimate the ionization rate using the standard deviation of the delay data. At the end, the paper proposes a method for calculating ionization rate using repeated frequency pulse burst delay data, and compares the calculated results with the simulation results, which have a good correspondence.
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Key words:
- repetition frequency /
- microwave breakdown /
- ionization rate /
- pulse delay /
- estimate
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表 1 实验结果
Table 1. Results of experiments
No. pressure/Pa electric intensity/(kV·cm−1) repetitive frequency/Hz pulse width /ns Tavg/ns A1 1000 0.92 20 20000 45 A2 1000 1.29 20 20000 22.5 B1 300 0.92 5 2000 35 B2 300 0.92 50 2000 25 B3 300 0.92 500 2000 15 C1 300 1.29 50 20 10 C2 300 1.29 50 200 10 C3 300 1.29 50 2000 10 C4 300 1.29 50 20000 10 表 2 击穿延时数据
Table 2. Breakdown delay data
electric field/
(kV·cm−1)breakdown delay time/ns fr=3 Hz fr=10 Hz fr=20 Hz fr=50 Hz fr=150 Hz 0.92 185.0 176.5 173.5 170.8 168.1 1.29 169.9 166.2 164.6 163.1 161.9 1.61 162.4 160.4 159.6 158.7 158.1 -
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