Studying Townsend and glow modes in an atmospheric-pressure DBD using mass spectrometry
Studying Townsend and glow modes in an atmospheric-pressure DBD using mass spectrometry
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DOI：
10.1088/1361-6595/aa9cb0
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发表时间：
2017-12
影响因子：
3.8
通讯作者：
K. McKay;D. Donaghy;Feng He;J. Bradley
中科院分区：
文献类型：
--
作者：
K. McKay;D. Donaghy;Feng He;J. Bradley
环境分子束质谱已被用来检查的操作模式和激励波形上的氦基大气压平行板介质阻挡放电的离子含量的影响。通过施加具有纳秒上升时间的10 kHz微秒电压脉冲和10 kHz正弦电压波形，分别产生明显不同的辉光和汤森模式。结果表明，在两种模式之间的优势离子种类的显着差异。在汤森模式中，分子氧离子，原子氧阴离子和一氧化氮阴离子是最丰富的物种，然而，在辉光模式中，水团簇离子和水合一氧化氮阴离子占主导地位。提出了几个假设来解释这些差异，包括低电子密度和能量的汤森模式，更有效的电离水分子通过潘宁电离和电荷交换与其他物种的辉光模式，和大的温度梯度，由于脉冲性质的辉光模式，导致更有利的条件下形成集群。
Ambient molecular beam mass spectrometry has been employed to examine the effects of the mode of operation and the excitation waveform on the ionic content of a helium-based atmospheric-pressure parallel plate dielectric barrier discharge. By applying 10 kHz microsecond voltage pulses with a nanosecond rise times and 10 kHz sinusoidal voltage waveforms, distinctly different glow and Townsend modes were produced, respectively. Results showed a significant difference in the dominant ion species between the two modes. In the Townsend mode, molecular oxygen ions, atomic oxygen anions and nitric oxide anions are the most abundant species, however, in the glow mode water clusters ions and hydrated nitric oxygen anions dominate. Several hypotheses are put forward to explain these differences, including low electron densities and energies in the Townsend mode, more efficient ionization of water molecules through penning ionization and charge exchange with other species in glow mode, and large temperature gradients due to the pulsed nature of the glow mode, leading to more favorable conditions for cluster formation.