A New Method for the Measurement of Low Concentrations of OH/O2 - Radical Species in Water by High-LET Pulse Radiolysis. A Time-Resolved Chemiluminescence Study

The new method described in this article allows the detection of low concentrations of radical species created in water for high linear energy transfer (LET) pulse radiolysis. The time-resolved chemiluminescence was used in a pulse radiolysis experiment at the Grand Accélérateur d'Ions Lourds (Caen, France) with an 40Ar18+ ion beam for the determination of radical yields. In water, for an LET of 280 eV/nm, the yield of OH is 2.2 × 10-8 mol/J. A minimum value of the eaq - and HO2/O2 - yields is obtained. These experimental G values are compared to those obtained for the same LET. They are in good agreement with the values in the literature. The sensitivity of the time-resolved chemiluminescence method allows the measurement of concentrations of radicals species as low as 2 × 10-7 M.