Research Of Phase-change Cooling Applied On Laser Mirror

This thesis takes the DICP's high power COIL (chemistry oxygen iodine laser) laser mirror as research object. The thermal distortion phenomenon, which takes pjace at the laser mirror's surface when it absorbs immense energy rapidly under the high power laser's irradiation, is analyzed in the paper. The phase-change cooling technology, as a rapid progress cross subject, has obvious advantages when used into the field of laser to solve this thermal distortion problem. But the research about theory and application in this field is still not perfect. Author designed a laser mirror with hole-array inner structure which filled with a specified phase-change material after consulting the existing technical literature, and carry out the experiment in the side of theory and application with it. It was proved that the Fourier heat conduction law is still suitable even the object be irradiated in a short time by high power laser. The mathematic model of heat conduction and phase changing was established through traditional heat conducting differential equation, and the Finite Element Method (FEM) was used to analysis it. ANSYS, an all-purpose FEM software, was selected to calculate the phase-change cooling mirror's temperature field and thermal distortion, and the same as a sample bronze mirror's as a contrast. At the same time we carried out the experiments with the two mirrors in the DICP's laser laboratory and have gotten the basically consistent result as the former calculation. All of this proves that it is effective by filling phase-change materials into the laser mirror for decreasing the mirror's thermal distortion.The paper put forward the ANSYS software on the numerical simulation of the phase-change cooled laser mirror for the first time. It would be constructive in the following experiments, such as the research of high performance phase-change cooling mirror, the choice of laser mirror materials, the optimization of interior structure and the development about phase-change materials, etc...