FOREIGN-GAS-INDUCED RELAXATION OF RYDBERG S-STATES AND D-STATES IN ATOMIC SODIUM

We have measured the He-, Ne-, and Ar-induced relaxation properties of the 3S-nS (3S-nD) superposition states of atomic sodium, where n ranges from 5 to 20 (4 to 34). The measurements were made using the trilevel echo effect. We find that the effective collisional cross section first increases (as a function of n) at low n, and then decreases to a lower asymptotic limit at high n. This behavior is similar to that previously observed for the 3S-nP series. We also find that the difference between the collisional cross sections for S and D series superpositions closely approximates the inelastic collision cross sections measured elsewhere for the d states. A theoretical description of the trilevel echo effect used to make the measurements is presented. © 1979 The American Physical Society.