THE INTERACTION OF BLACKBODY RADIATION WITH XENON RYDBERG ATOMS

Effects due to the interaction between the 300K background blackbody radiation (BBR) and xenon nf Rydberg atoms are reported. Transitions to nearby d and g levels are observed and the transition rates are found to be consistent with the predictions of a simple theoretical calculation which makes use of electric dipole matrix elements obtained by use of the quantum defect method. When the radiation background is reduced to that appropriate to a black body at liquid nitrogen temperature by cooling the apparatus, the transition rates are also observed to decrease. The reduction in the transition rates to the d and g states is consistent with the calculated decrease in the ambient blackbody flux. The total net depopulation rate of the f states is reduced as well when the temperature of the environment is lowered. The change in the observed lifetimes of the f states is in good agreement with the calculated decrease in the blackbody-induced depopulation rate