Eur. Phys. J. D 44, 9-16 (2007)
https://doi.org/10.1140/epjd/e2007-00147-0

Oscillator strength measurements of the 3p ↦ nd Rydberg transitions of sodium

Atomic and Molecular Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad, 45320, Pakistan

Corresponding author: ^a baig@qau.edu.pk

Received: 22 December 2006
Revised: 16 February 2007
Published online: 4 May 2007

Abstract

We report new measurements of the oscillator strengths of the 3p ²P_3/2 ↦nd ²D_{5/2, 3/2} and 3p ²P_1/2 ↦ nd ²D_3/2 Rydberg transitions of sodium using a thermionic diode ion detector in conjunction with the Nd:YAG pumped dye lasers. The ns ²S_1/2 and nd ²D_5/2,3/2 Rydberg series have been recorded via two-step excitation, from the 3p ²P_3/2 and 3p ²P_1/2 intermediate states. Employing the saturation technique, the photoionization cross sections from the 3p ²P_3/2 and 3p ²P_1/2 intermediate states at the first ionization threshold are determined as 7.9(1.3) Mb and 6.7(1.1) Mb respectively. The f-values of the Rydberg transitions are calibrated with the photoionization cross section measured at the first ionization threshold and compared with the earlier data.