Positron annihilation lifetime spectroscopy(PALS) is a useful technique for nano-defects identification in materials.The positron annihilation status and electrondensity distribution in materials can be obtained by PALS.In this paper
based on characteristics of the genetic algorithm(GA) global search and generation of the initial value randomly
a multi-exponential function fitting of theoretic PALS is attempted
and the curve fitting is performed by using MATLAB.The life expectancy of each component and the corresponding intensity is achieved.The results deduced from the GA and the LifeTime9.0 are compared.The parameters PALS are analyzed by the GA
which does not request assigning experiential initial value and does not involve local optimum.