Linewidth oscillations in the 5d(3/2)nd autoionizing series of barium

摘要

The first autoionization region of barium was studied using a single-color two-photon excitation scheme. The resonance energies and linewidths of barium 5d(3/2)nd D-1(0,2) series members were obtained by fitting each spectral line with a Beutler-Fano profile function. The quantum defects of the series were calculated using the obtained resonance energies. The behavior of the linewidth and quantum defect of the series members for n = 8 to 30 was then studied to find out about different interactions involving this autoionizing series such as inter-series coupling. Atomic Ba vapor was produced in a hot-pipe oven, and a tunable dye laser pumped by an excimer laser was used to excite autoionizing Rydberg states. We observed spectral linewidth oscillations in the range of the main quantum numbers 8 to 24, and explained this phenomenon based on interconfiguration interaction among autoionizing series of Ba.