The undercooling and solidification of 150 μm and 185 μm droplets of Sn 5%Pb alloy prepared by the uniform droplet spray (UDS) process have been investigated. The enthalpy of the droplet has been measured by non adi...The undercooling and solidification of 150 μm and 185 μm droplets of Sn 5%Pb alloy prepared by the uniform droplet spray (UDS) process have been investigated. The enthalpy of the droplet has been measured by non adiabatic calorimetric method as a function of the flight distance. A droplet solidification simulation model has been used to compare with the experimental data. The results show that the enthalpy released by the droplets in the calorimeter is 11.88 J/g and 22.29 J/g less than the simulated values up to a certain flight distance at 0.485 m and 0.460 m for 150 μm and 185 μm droplets respectively, but agrees with the expected values at larger distance. The nucleation of the droplets takes place at the distance where the experimental and simulated enthalpy values agree. The droplets quenched before nucleation solidify into metastable supersaturated solid solution and have large undercooling. The formation of the metastable structure in the droplets has been verified metallographically and by calculations based on a thermodynamic model.展开更多
Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption effici...Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption efficiency,radiation efficiency,and spectral efficiency.The dependence of drive laser pulse duration and laser intensity on EUV-CE is investigated.The results show that at some appropriate laser intensity,where the sum energy of the thermal conduction,out-off band radiation and plasma plume kinetic losses is at a minimum,the EUV-CE should reach a maximum.The EUV-CE predicted by the present simple model is also compared with the available experimental and simulation data and a fair agreement between them is found.展开更多
文摘The undercooling and solidification of 150 μm and 185 μm droplets of Sn 5%Pb alloy prepared by the uniform droplet spray (UDS) process have been investigated. The enthalpy of the droplet has been measured by non adiabatic calorimetric method as a function of the flight distance. A droplet solidification simulation model has been used to compare with the experimental data. The results show that the enthalpy released by the droplets in the calorimeter is 11.88 J/g and 22.29 J/g less than the simulated values up to a certain flight distance at 0.485 m and 0.460 m for 150 μm and 185 μm droplets respectively, but agrees with the expected values at larger distance. The nucleation of the droplets takes place at the distance where the experimental and simulated enthalpy values agree. The droplets quenched before nucleation solidify into metastable supersaturated solid solution and have large undercooling. The formation of the metastable structure in the droplets has been verified metallographically and by calculations based on a thermodynamic model.
基金Supported by the National Natural Science Foundation of China under Grant No. 61078024
文摘Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption efficiency,radiation efficiency,and spectral efficiency.The dependence of drive laser pulse duration and laser intensity on EUV-CE is investigated.The results show that at some appropriate laser intensity,where the sum energy of the thermal conduction,out-off band radiation and plasma plume kinetic losses is at a minimum,the EUV-CE should reach a maximum.The EUV-CE predicted by the present simple model is also compared with the available experimental and simulation data and a fair agreement between them is found.
