We describe a new nozzle for spectroscopic studies of reactive species in pulsed supersonic jets. This nozzle was designed as a cheap alternative to laser ablation methods for producing metal-containing species. It employs an electrical discharge to produce metal atoms by argon ion sputtering at the cathode. These metal atoms can then be mixed with appropriate reagents to produce metal-containing species before expansion into vacuum. To avoid rapid carbon deposition onto the metal source electrode when carbon-containing reagents are used, the reactive precursor must be kept away from the metal-sputtering region. Consequently, a dual channel nozzle has been developed in which two pulsed gas sources are mixed at a common point prior to expansion. This has been tested by preparing a number of spectroscopically well characterised metal-containing species. The results show that this nozzle is a viable alternative to laser ablation for producing metal-containing species. The spectroscopic data, obtained using laser-induced fluorescence, demonstrate that the nozzle has good pulse-to-pulse stability and can maintain signal amplitude for > 80 h before electrode replenishment is required.
我们介绍了一种新的喷嘴,用于对脉冲超音速喷流中的反应物进行光谱研究。这种喷嘴是作为激光烧蚀法的廉价替代方法设计的,用于产生含
金属的物种。它采用放电技术,通过阴极的
氩离子溅射产生
金属原子。然后,这些
金属原子可以与适当的试剂混合,在膨胀到真空中之前产生含
金属的物质。在使用含碳试剂时,为避免碳迅速沉积到
金属源电极上,反应前驱体必须远离
金属溅射区。因此,我们开发了一种双通道喷嘴,其中两个脉冲气源在膨胀前在一个共同点混合。通过制备一些光谱特性良好的含
金属物种对其进行了测试。结果表明,这种喷嘴可替代激光烧蚀法生产含
金属物质。利用激光诱导荧光获得的光谱数据表明,喷嘴具有良好的脉冲间稳定性,在需要补充电极之前,可以保持信号振幅大于 80 小时。