Laser induced fluorescence spectroscopy (LIF) is used to measure absolute ground state densities of nitric oxide (NO) in the effluent of the COST reference microplasma jet (COST-jet) with three-dimensional spatial resolution. The jet is operated in helium with a nitrogen/oxygen admixture. The experiments are performed with the jet expanding into open air and into a controlled He/synthetic air atmosphere. The most efficient production of NO is found at a 0.5% admixture of N₂/O₂ at a ratio of 4/1, that is considered to be synthetic air. Maximum NO densities of 3.25 10¹⁴ cm⁻³ and 4.5 10¹⁴ cm⁻³ are measured in the air and He/synthetic air atmosphere, respectively, at an axial distance of 2 mm from the nozzle. The distribution patterns are found to transit into a turbulent regime for air atmosphere at greater axial distances, while in the He/synthetic air atmosphere this effect is not observed. It is found that the expansion of the region of high NO density in the effluent is strongly coupled to the helium flow. Furthermore, the NO density is found to depend on the absolute feed gas flow, i.e. its maximum decreases as a function of the gas flow. This is a result of the longer residence time of the gas in the active plasma volume at lower gas flows and higher energy densities. For very high values of the applied radio frequency power the NO density is saturated. From time resolved measurements of the LIF signals the quenching coefficient for the NO(A ²Σ⁺) state by air is found to be k _u,air = 4.2(0.5) 10⁻¹¹cm³s⁻¹, while quenching by He is negligible, k _u,He ⩽ 1 10⁻¹⁴cm³s⁻¹. The amount of ambient air intruding the helium effluent is determined as well.

激光诱导荧光光谱法（LIF）用于以三维空间分辨率测量COST参考微等离子体射流（COST-jet）流出物中一氧化氮（NO）的绝对基态密度。射流在氦气中与氮气/氧气混合气操作。在喷射流扩展到露天和受控的He /合成空气气氛中进行实验。发现N ₂ / O _2的混合比例为4/1的N ₂ / O ₂含量为0.5％时，NO的产生效率最高，这被认为是合成空气。最大NO浓度为3.25 10 ¹⁴ cm ^-3和4.5 10 ¹⁴ cm ^-3分别在空气和He /合成空气气氛中，在距喷嘴2 mm的轴向距离处进行测量。发现分布模式在更大的轴向距离处转变为空气气氛的湍流状态，而在He /合成空气气氛中未观察到这种效应。发现废水中高NO浓度区域的膨胀与氦气流动密切相关。此外，发现NO密度取决于绝对进料气流，即其最大值随气流的变化而降低。这是由于在较低的气流和较高的能量密度下，气体在活性等离子体体积中的停留时间更长。对于所施加的射频功率的非常高的值，NO密度达到饱和。阿 ² Σ ⁺）通过空气状态被发现是ķ _Ù，空气= 4.2（0.5）10 ^-11厘米^3个小号^-1，而由他淬火是可以忽略的，ķ _ü，他⩽1 10 ^-14厘米^3个小号^{- 1}。还确定了侵入氦气流出物的环境空气量。