Molecular Dynamics Simulation Application In Defect Fused Silica With Laser Irradiation

Optical materials have attracted more and more attention in scientific research.The application of surface research of fused silica materials is very broad.As a very important optical element in the laser inertial confinement fusion experimental device,the fused silica optical element's resistance to damage and its impact on the quality of light velocity is of utmost importance.This dissertation focuses on the dynamic process of laser irradiation of fused quartz material,discusses the change of the microstructure of fused silica amorphous material during laser irradiation,and the influence of the type and size of surface defects on the microstructure of fused silica.The evolution of the microstructure parameters such as bond lengths,bond angles,coordination numbers of the atomic atoms,etc.of fused silica with laser parameters,defect types,and dimensions are given in detail.At the same time,the theoretical analysis of the effects of ultraviolet laser on the properties of optical components is performed,which provides a theoretical basis for improving the loading capacity of optical components in laser confinement fusion devices.The main contents and conclusions of this paper are as follows:1.The establishment of amorphous structure of fused silica.That is,the silica crystal structure was established through Materials Studio.Based on the experimental process of fused silica generation,the amorphous structure of fused silica was obtained by simulation using the molecular dynamics software DL_POLY.2.Establishment of a study procedure for the kinetic process of laser-irradiated fused quartz.A laser-loaded molecular dynamics model and a fused silica surface defect model(cube,cone,hemisphere,cylinder)were constructed to establish a LAMMPS program to study the molecular dynamics of laser-irradiated fused silica.3.Using the fused silica structural model and the LAMMPS molecular dynamics program established above,the computational simulation of the laser radiating ideal fused silica structural dynamics process was performed.The parameters(bond length,bond angle,coordination number,etc.)characterizing the microstructure of fused silica after irradiation were obtained,and the effects of different laser irradiation parameters on the microstructure of ideal fused silica were analyzed.4.Using the above-mentioned defect-containing fused-silica structure and the LAMMPS molecular dynamics program,the molecular simulation of the molecular dynamics of the fused fused-silica structure with laser irradiation was performed.The effects of the presence of four different defects on the arrangement of fused silica atomic structure,including cubic defects,cone defects,hemispherical defects and cylinder defects,were discussed under laser irradiation with the same parameters.5.Change the size of different defects on the surface of fused silica,and study the effect of laser irradiation on the change of the microstructure of fused silica.6.From a theoretical point of view,analyze the effect of laser irradiation on the structure,performance and resistance to damage of fused silica.It provides a theoretical basis for improving the loading capacity of optical components in laser confinement fusion devices.