Emission spectra of a pulse needle-to-plane corona-like discharge in conductive aqueous solutions
Emission spectra of a pulse needle-to-plane corona-like discharge in conductive aqueous solutions
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DOI：
10.1088/0963-0252/21/5/055031
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发表时间：
2012-10
影响因子：
3.8
通讯作者：
M. Šimek;M. Člupek;V. Babický;P. Lukeš;P. Šunka
中科院分区：
文献类型：
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作者：
M. Šimek;M. Člupek;V. Babický;P. Lukeš;P. Šunka
我们探索了在导电水溶液中由周期性高压脉冲产生的正电晕样放电的基本光学和电学特性。在针-板电极几何结构中获得了放电的发射光谱，并在溶液电导率为100和500µS cm - 1的纳秒时间分辨率下在紫外-可见-近红外光谱范围内进行了分析。最重要的发射特征是由于HI， OI， OII和OH的电子激发。我们发现有证据表明，选定的HI和OI转变具有显著的随时间变化的线形增宽。所观察到的加宽归因于动态Stark和压力加宽机制，并随着水溶液电导率的增加而显著增加。通过将单个Voigt峰函数拟合到观察到的Hα谱估计电子密度，可以达到ne × 4 × 1018 cm - 3（在100µS cm - 1溶液电导率下tD = 300 ns）和ne × 5 × 1018 cm - 3（在500µS cm - 1溶液电导率下tD = 1µS）。在放电衰减期间，部分分解的OH发射旋转结构的时间演化达到最大值，相对于流光点火，其开始时间明显延迟。
We explored basic optical and electrical characteristics of a positive corona-like discharge produced in conductive aqueous solutions by periodic high-voltage pulses. Emission spectra of the discharge were acquired in a needle-to-plate electrode geometry and analysed in the UV–vis–NIR spectral range with nanosecond time resolution for the solution conductivity of 100 and 500 µS cm−1. The most important emission features are due to electronic excitation of HI, OI, OII and OH species. We found evidence of significant time-dependent line-shape broadening of selected HI and OI transitions. The observed broadening is attributed to the dynamic Stark and pressure broadening mechanisms and significantly increases with the aqueous solution conductivity. Electron densities were estimated by fitting a single Voigt peak function to the observed Hα profiles, and can reach as much as ne ≅ 4 × 1018 cm−3 (tD = 300 ns at 100 µS cm−1 solution conductivity) and ne ≅ 5 × 1018 cm−3 (tD = 1 µs at 500 µS cm−1). Temporal evolution of the partially resolved rotational structure of the OH emission reaches a maximum during the discharge decay, with the onset significantly delayed with respect to the streamer ignition.