Photoabsorption spectra of silver in the 4d-subshell excitation region

High-resolution measurements of the photoabsorption spectra of silver in the 4d-subshell excitation region are reported using synchrotron radiation as the background source of the continuum. The spectra were recorded in the first order of a 3-m spectrograph equipped with a 6000-lines/mm holographic grating at a dispersion of 0.5 nm/mm and using photographic detection. Rydberg series have been observed converging to four conspicuous limits built on the 4d(9)5s parent ion configuration 4d(10)5s S-2(1/2)-> 4d(9)5s(D-3(3,2,1),D-1(2)) np and nf (J=1). The high-resolution data reveal extended Rydberg series, accurate term energies, quantum defects, and widths of the autoionizing resonances. The resonance energies and widths of the leading members of the series have been determined using multichannel quantum defect theory.