Optical oscillator strengths for 3(2)S -> 4(2)P and 3(2)S -> 5(2)P excitations of Na

The electron-energy-loss-spectrum of sodium has been measured in discrete r egion at a 1.5 keV impact energy and a mean scattering angle of 0 degrees. The relative optical oscillator strength density spectrum of the valence sh ell of sodium was established by using the dipole (e, e) method and then no rmalized to the theoretical optical oscillator strength of the 3(2)S --> 3( 2)P excitation. The optical oscillator strengths of the 3(2)S --> 4(2)P and 3(2)S --> 5(2)P excitations obtained in the present work are 0.014 +/- 0.0 02 and 0.0026 +/- 0.0004, respectively. Theoretical values of optical oscil lator strengths for 32S --> n(2)P (n = 3 - 5) excitations of sodium were ob tained by rising the relativistic configuration interaction method, which a re 0.97, 0.012, and 0.0026, respectively.