Autoionizing Rydberg series(np′,nf′)of Ar investigated by stepwise excitations with lasers and synchrotron radiation

1.611 0.011, 1.683 0.013, 1.688 0.010, and 0.016 0.005, respectively. Our values are in excellent agreement with theoretical prediction. The spectral line shapes of autoionizing Rydberg states are analyzed with a Beutler-Fano profile. Reduced autoionization linewidths for the np1 / 20n =1 1–1 6 series vary in the range 2549– 4145 cm �1 , and the nf5 / 22n =9–1 1 series in 186– 247 cm �1 in reasonable agreement with theoret