Spur decay kinetics of the solvated electron in heavy water radiolysis

Spur decay kinetics of the hydrated electron following picosecond pulse rad iolysis of heavy water have been measured using a time-correlated absorptio n spectroscopy (TCAS) technique. The TCAS data collected for the first 40 n s of the decay was matched up with single-shot transient digitizer data out to microsecond time scales. The decay shape in heavy water looks exactly l ike the decay in light water except in the first 10 ns. The "time zero" sol vated electron yield in heavy water radiolysis must be approximately 7% lar ger than in light water, to match the best available scavenger product meas urements. We propose an explanation in terms of the larger distances travel ed by electrons in heavy water prior to localization. The implication is th at presolvated H2O+ "holes" are very efficient scavengers for the presolvat ed conduction band electrons.