Study on Discharge Characteristics of Ionizing Sensor Based on Hydrodynamics

The ionized gas sensor has the characteristics of fast response, high accuracy and easy integration, and can quickly and accurately sense the gas concentration, type and other physical quantities. Due to the characteristics of the inter-electrode discharge process of the ionization sensor, such as dense electron collision frequency, high efficiency of local collision ionization, weak overall ionization intensity, and complex electron emission mechanism, it is difficult to explore the transport mechanism of spatiotemporal electric field-mixed ions. In this paper, based on the hybrid model of hydrodynamics, the dynamic electric field in the N2–O2 space of the ionization sensor is numerically simulated, and the discharge process is simulated. The results show that the positive and negative ions have a great influence on the spatial and temporal distribution of the electric field intensity in the interpolar space; Through the calculation of the development law of electron temperature, it is found that the space electron obtains energy through the joule heat effect of the space electric field; Finally, through the calculation of the change of electron current and ion current density, it is found that the discharge current density is composed of the superposition of electron current density and ion current density, and the secondary electron emission is an important factor for the self-sustaining of space discharge. The research reveals the discharge mechanism of the ionization sensor, and provides a reference for the application and promotion of atmospheric pressure micro plasma effect in the field of gas discharge. At the same time, the hydrodynamic mixing model used in the research can also be extended to the fields of micro plasma control and mixed ion detection, which has important practical significance.