Study On The Formation Of CN Radical In Nitrogen/alkane Glow Discharge

Plasma is composed of various types of ions,electrons and neutral matter,and is the main component of cosmic matter.Gas discharge is one of the methods of artificial plasma,which is widely used in basic science and application fields.The components and interactions of atoms,molecules,radicals and excited states in plasma can be characterized qualitatively and quantitatively by spectroscopic technique.In this paper,we study the possible evolution of Titan atmosphere by using the spectrum simulation of CN free radical molecule.CN radicals play an important role in the process of life formation.In the early planetary atmosphere,the formation of CN was closely related to nitrogen and alkanes.Taking Titan's atmospheric composition as a reference,the experiment used nitrogen and alkanes to simulate the early atmospheric environment,and the simulated atmosphere was subjected to glow discharge to measure the absorption spectrum of CN radicals to study the effects of alkanes concentration,pressure,and discharge current on CN generation.In a low-pressure glow discharge of a mixed gas of nitrogen and an alkane,experiments show that when the concentration of CN radicals is optimal,the pressure ratio of methane,ethane,and propane.When the ratio of nitrogen to alkane is kept constant and the total pressure is changed,the concentration of CN radicals increases with the increase of the total pressure at a lower pressure;when the total pressure exceeds a certain pressure,the trend of alkanes is different.However,in any alkane nitrogen glow discharge and any gas pressure ratio,the effect of discharge current on the formation of CN radicals is almost linearly increased.On the basis of the optimum conditions for the formation of CN radicals,a small amount of trace water vapor,carbon dioxide and carbon monoxide in Titan atmosphere were added to the mixture of alkane and nitrogen.The results show that the formation of CN radicals can be inhibited by adding a small amount of these gases during the discharge of the mixture of nitrogen and methane.