Lifetime Of High Rydberg States In Li

Rydberg atoms have properties of large radius, large polarizability, long radiative lifetime. It has been used in many fields. The lifetime can reflect the structure and energy level information of Rydberg atoms. So the radiative lifetime of high Rydberg states have been widely used in astronomical spectral analysis, space physics, theoretical calculation and study of atomic structure, plasma physics, gas discharge, controlled thermonuclear fusion and laser isotope separations. The Rydberg atom is simpler than ordinary atom, so it can be used as a test site for physical research. The radiative lifetime of high Rydberg states need to be studied to test experimental methods and make up for the deficiency of the experimental data.At present the most of theoretical calculation on lifetime only focus on low-lying atomic states. The Coulomb approximation cannot be directly applied to cases with n> 30. Theodosiou proposed a realistic atomic potential and calculated the lifetime of alkali-metal Rydberg states with principal quantum numbers n lower than 21. Li Baiwen et al. have got the lifetime of alkali-metal atom Rydberg states with n up to 50. Li Guosheng et al. used a simple analytical wave function with node correction calculated the lifetime of alkali-metal Rydberg states with n up to 40. In 2009, Beterov et al. using quasiclassical formulas to calculate the lifetime of alkali-metal Rydberg states with n up to 80. Thus it is desirable to have a theoretical method to calculate lifetime of alkali-metal Rydberg states with n higher than 80. Calculating the lifetime with higher principal quantum number is very difficult. It is because calculating the radial matrix elements of alkali-metal Rydberg states with higher n is very difficult. We use alkali-metal parametric model potential, B-spline technique and double precision numerical integral, obtaining the radial matrix elements of Li atom with n reach 140. Then calculating the radiative lifetime of Li atom with n lower than 140. The results agree well with the experimental values and other theoretical ones. Our work of high states can not only provide theoretical basis for related experiments, but also provide guidance for the future experiments.