Even-parity bound and autoionizing Rydberg series of the samarium atom

Two-colour two-step resonance ionization mass spectrometry is employed to observe the even-parity Rydberg levels with unique angular momentum J = 1. The bound and autoionizing. Rydberg series converge at three different ionic states of samarium (Sm), namely, 4f(6) (F-7) 6s [F-8(1/2)], 4f(6) (7F) 6s [F-8(3/2)] and 4f(6) (F-7) 6s [F-8(5/2)]. Apart from the Rydberg levels, 80 new autoionizing energy levels with total angular momentum J = 1 are also discovered. Analyses of the Rydberg series lead to a more precise determination of the first ionization potential of atomic Sm. The value of the ionization potential obtained is 45 519.64 +/- 1.39 cm(-1).