Loss Rates For High-N, 49 Less Than Or Similar To N Less Than Or Similar To 150, 5sns (S-3(1)) Rydberg Atoms Excited In An Sr-84 Bose-Einstein Condensate

Measurements of the loss rates for strontium n(3)S(1) Rydberg atoms excited in a dense Bose-Einstein condensate are presented for values of principal quantum number n in the range 49 less than or similar to n less than or similar to 150 and local atom densities of similar to 1 to 3 x 10(14) cm(-3). Two main processes contribute to loss, associative ionization, and state changing. The relative importance of these two loss channels is investigated, and their n and density dependences are discussed using a model in which the Rydberg atom loss is presumed to involve a close collision between the Rydberg core ion and ground-state atoms. The present measurements are compared to earlier results obtained using rubidium Rydberg atoms. For both species the observed loss rates are sizable, similar to 10(5) - 10(6) s(-1), and limit the timescales over which measurements involving Rydberg atoms immersed in quantum degenerate gases can be conducted.