Mechanism of droplet generation and optical emission of metal atoms in atmospheric-pressure dc glow discharge employing liquid cathode
Mechanism of droplet generation and optical emission of metal atoms in atmospheric-pressure dc glow discharge employing liquid cathode
复制标题
液体阴极常压直流辉光放电中金属原子液滴生成和光发射机制
DOI：
10.1088/1361-6595/ab6abc
复制
发表时间：
2020
影响因子：
3.8
通讯作者：
Sasaki Koichi
中科院分区：
文献类型：
--
作者：
Shirai Naoki;Suga Goju;Sasaki Koichi
实验研究了电解液阴极常压直流辉光放电中金属原子的液滴产生和发光机理。我们研究了采用电解液阴极的常压直流辉光放电中电解液表面的动力学、气相液滴的密度及其空间分布和光发射强度之间的相关性。实验结果揭示了金属原子的液滴产生和光学发射的机理。液滴密度与光学发射强度之间的相关性表明，液滴在金属原子从电解液到气相的传输过程中具有重要作用。从液滴中产生金属原子似乎是光学发射的一种机制。我们提出了两种从电解液阴极产生液滴的机制。首先是电解液表面形状的扭曲。通过类似于电喷雾的过程，从锥形电解液表面的尖端产生液滴。第一种机制是在放电的时间演化的早期阶段启动液滴的产生。第二种机理是钠颗粒与水的爆炸反应。我们推测，钠粒子是由气相中的钠原子产生的。一旦第二种机制被启动，就实现了钠原子、钠粒子和氯化钠液滴的自持产生，导致金属原子的强烈光学发射。
The mechanism of the droplet generation and the optical emission of metal atoms in an atmospheric-pressure dc glow discharge employing an electrolyte cathode were investigated experimentally. We examined the correlation among the dynamics of the electrolyte surface, the density and its spatial distribution of gas-phase droplets, and the optical emission intensity in an atmospheric-pressure dc glow discharge employing an electrolyte cathode. The experimental results reveal the following mechanism for the droplet generation and the optical emission of metal atoms. The correlation between the droplet density and the optical emission intensity indicates the importance of droplets in the transport of metal atoms from the electrolyte to the gas phase. The production of metal atoms from droplets seems to be a mechanism of the optical emission. We propose two mechanisms for the generation of droplets from the electrolyte cathode. The first is the distortion in the shape of the electrolyte surface. Droplets are produced from the tip of the cone-shaped electrolyte surface via a process similar to electrospray. The first mechanism works for the initiation of the droplet generation in the early stage in the temporal evolution of the discharge. The second mechanism is the explosive reaction between Na particulates and water. We speculate that Na particulates are produced from Na atoms in the gas phase. Once the second mechanism is switched on, the self-sustained productions of Na atoms, Na particulates, and NaCl droplets are realized, resulting in the intense optical emission of metal atoms.