Measurement with a White Power Spectrum

The solvent was toluene. The same sample has been measured with PCS, TD-FRS with a single long exposure pulse, and TDFRS with a pseudostochastic exposure sequence (At = 140 Jus,N=2047), which has been optimized by the 1-spin-flip optimization described in the previous section. The PCS experiment was originally measured with X = 647 nm at an angle of 90° and has been shifted to 

The ratio of 6.8 for the two peak areas from stochastic TDFRS is close to the value of 5.9 as expected from the concentration ratio and the refractive index increments of the two PS, which depends on molar mass due to end-group effects. The thermal diffusion coefficient DT= 1.12 x 10 7 cm2 (sK) l is in excellent agreement with the value found previously in our laboratory [36]. 

The PCS rate distribution shows only the large peak of the slow mode, corresponding to the high molar mass component. The tiny peak at Tl appears at too high rates and is probably an artifact. 

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