Configuration Designing And Numerical Demonstration Of The Water Jet Cooled Mirror

Thermal deformation of the mirror in a resonator is a key factor that hinders theimprovement of the system performance in high power lasers. Water-cooled techniqueis the most widely method used in cooling of high power lasers. Kinds of water-cooledmirrors have been studied by researchers in the world. Research teams of the UnitedStates and Russia have done a lot of work and the performances of their mirrors are verygood. In China, study of micro-channel silicon mirror has been carried out by ChengZuhai in detail. Several factors affect the application of the water-cooled silicon mirror,which are complex structure, difficulty in producing mirrors with large aperture,inhomogeneity of mirror deformation resulted from lateral injecting of the water.The jet-cooled technique has been widely used in cooling of the turbine and themicro-electronics chips. In the present paper, a water jet cooled mirror was designedand a validated numerical model was established to investigate the performance of themirror.With the model, the factors which induce deformation of the water jet cooledmirror were analyzed. Some rules in configuration designing of the water jet cooledmirrors were obtained and configuration optimizations of the water jet cooled mirrorwere also studied. Results showed that SiC was a better choice in comparison with othermaterials and performance of the water jet cooled mirror is better than the water-cooledmirrors with other configurations.According to the characters of the high power chemical laser systems, the factorswhich cause deformation of the water-cooled mirrors were analyzed and deformation ofthe water-cooled mirrors with large aperture was calculated. Some rules in the design ofthe water-cooled mirrors were obtained.A water jet cooled copper mirror was produced and hydro-experiments werecarried out in order to validate the numerical model. It is showed that performance ofthe water jet cooled mirror is excellent. Experimental results are approximatelyconsistent with the numerical results and the correctness of the model was demonstrated.From the above results, conclusions are obtained as follows. Firstly, the mirrorwith water jet cooled configuration have a good performance with little deformation,simple structure and good uniformity. Secondly, SiC was a better choice compared withother materials. Thirdly, the water jet cooled mirror can be used in high power chemicallasers.