BLACKBODY-RADIATION-INDUCED RESONANCES BETWEEN RYDBERG-STARK STATES OF NA

We report on measurements of the population of Rydberg states of Na in a constant electric field that result when 300-K blackbody radiation induces transitions from initial states with \m\ = 0,1 to neighboring states. Our measurements included comprehensive ranges of initial stat es (n(i)=24-29), repopulation times (t(d)=0-50 mu s), and fields (F-s =175-712 V/cm). We find that the population is redistributed nonunifor mly among states neighboring the initial state, reflective of sharp re sonances between the states. By comparing calculations of transition p robabilities in Na to the data for F-s=200 V/cm we were able to identi fy the populated states. Comparisons with calculations in H reveal tha t these resonances are hydrogenic.