Research On The Mechanism And Experiment Of Ice Core Melting Cutting Based On CO₂ Laser

Polar ice cores have important scientific value for the study of the earth system.The physical and chemical analysis of ice cores drilled from the polar regions can understand the changing trend of the earth's climate and draw the laws of ice cap formation and evolution.The first step in ice core research is to cut the ice core into pieces.The traditional ice core cutting method is saw cutting.This cutting method has many disadvantages:1.It is easy to pollute the ice core;2.It produces cracks and damages the sample;3.When cutting,a large slit is produced,which reduces the utilization rate of the ice core.The lack of ice core dating information.In view of the above-mentioned problems in ice core cutting,this paper proposes a new method of using high-energy laser to cut ice core—laser ice melting cutting method.This method has the advantages of high efficiency,high directivity and low loss,which can effectively avoid the occurrence of ice core cracks,reduce the width of the cutting slit and will not cause pollution to the ice core.This paper uses a combination of theoretical research,numerical simulation and experimental research to study the efficiency and groove width of CO₂ laser cutting ice cores.Through theoretical research,the optical characteristics of ice are analyzed,and the optimal wavelength of the laser for ice core cutting is obtained.Based on the theoretical analysis results,a single-beam CO₂ laser rotating ice core model is established in the COMSOL Multiphysics software to explore different laser powers.The surface temperature of the ice core changes when acting on ice cores with different rotation speeds,and the efficiency of laser melting and cutting ice cores is initially obtained;finally,through the laser cutting ice core experiment,the ice cores are subjected to different laser power and ice core rotation speeds.And this article explored the influence mechanism of laser parameters and mechanical motion parameters on the groove width of laser cutting ice core and melting ice cutting efficiency.Through the investigation of the above-mentioned problems,this paper found that CO₂ laser is a kind of infrared light,and the absorption coefficient of CO₂ laser by ice is obviously better than other types of lasers.Therefore,this paper chooses CO₂ laser to conduct numerical simulation and experimental research on ice core cutting.Numerical simulations have obtained the efficiency of laser cutting ice cores,and then carried out CO₂ laser cutting experiments on artificial ice cores.Different power lasers were selected to cut ice cores with different speeds.It was found that the laser power increased at the same ice core speed.The groove width increases,and the cutting efficiency improves.Under the same laser power,the ice core speed increases,the groove width becomes narrower,and the cutting efficiency improves.Based on the above test results,it can be seen that the laser power is reasonably reduced and the ice core is increased during the ice core cutting process.Rotation speed can effectively reduce ice core loss and improve ice core cutting efficiency.There is little difference between the simulation and the test results,which are mutually supportive.It was also found in the experiment that the lower the temperature of the ice core,the higher the cutting efficiency and the wider the groove width.The research is done in this paper provides theoretical support for the design of subsequent laser drilling tools,and provides guidance for the application of subsequent laser drilling tools.