Influences of voltage shape and discharge gas on the temporally and spatially resolved emission characteristics of tin in a planar dielectric barrier discharge
Influences of voltage shape and discharge gas on the temporally and spatially resolved emission characteristics of tin in a planar dielectric barrier discharge
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DOI：
10.1016/j.sab.2019.105695
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
S. Burhenn;J. Kratzer;J. Dědina;J. Franzke
中科院分区：
文献类型：
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作者：
S. Burhenn;J. Kratzer;J. Dědina;J. Franzke
选择一个合适的电源有关的形状的激励电压和放电气体的类型的元素分析与介质阻挡放电是不平凡的。两者都显著影响分析物信号。通过常规方法，例如电感耦合等离子体质谱法或原子吸收光谱法，可以找到最佳条件，然而，特定参数集产生理想信号的原因隐藏在DBD的详细特性中。这些现象发生在纳秒到微秒的狭窄时间尺度上，并且具有观察的挑战性。因此，在平面介质阻挡放电原子化器中的锡的发射分布进行了研究，通过时间和空间分辨的光学发射光谱，通过改变放电气体的类型和形状的激励电压。后者是通过应用正弦或方波电源来实现的。时间分辨的发射曲线表明，在正弦激励的情况下，功率分布在一个较长的时间在几个放电事件，而与方波激励的功率耦合到介质阻挡放电在一个密集的脉冲。空间分辨的发射信号指示了每个电源的介质阻挡放电内的Sn的不同激发点。在等离子体中，这是持续的方波电源的Sn发射，是不显着的影响，由放电气体从氩气到氦气的变化。然而，对于由正弦电源激发的等离子体中的发射信号，氦气有不利的影响。
Choosing a suitable power supply concerning the shape of the excitation voltage and the type of discharge gas for elemental analysis with a dielectric barrier discharge is not trivial. Both significantly affect the analyte signal. By means of conventional methods such as inductively coupled plasma mass spectrometry or atomic absorption spectrometry optimal conditions can be found, however the reason why the specific parameter set results in ideal signals is hidden in the detailed characteristics of the DBD. These phenomena occur on a narrow time scale of nanoseconds to microseconds and are challenging to observe. Therefore, the emission profiles of tin in a planar dielectric barrier discharge atomizer were studied by means of temporally and spatially resolved optical emission spectroscopy by varying the type of discharge gas and the shape of the excitation voltage. The latter was realized by applying either a sinusoidal or a square wave power supply. The temporally resolved emission profile showed that in case of sinusoidal excitation the power is distributed over a longer time in several discharge events, whereas with square wave excitation the power is coupled to the dielectric barrier discharge in one intensive pulse. The spatially resolved emission signals indicated a different point of excitation of Sn within the dielectric barrier discharge for each power source. The Sn emission in a plasma, which was sustained by the square wave power supply, was not significantly influenced by the change of the discharge gas from argon to helium. However, for the emission signal in a plasma excited by the sinusoidal power supply, helium had an adverse effect.