UV intensity measurement of 308 nm excimer lamp using chemical actinometer

Photohydrolysis of 3,4-dimethoxynitrobenzene in alkaline media is used for the determination of the ultraviolet (UV) intensity from a xenon chloride e xcimer lamp providing intense narrow band radiation at lambda = 308 nm (XeC l*). The intensity measurement is based on UV spectral absorption measureme nt of the 2-methoxy-5-nitrophenolate anion formation from photohydrolysis o f 3,4-dimethoxynitrobenzene. This actinometer is convenient for photolysis studies and measurements of UV intensities at wavelengths between 200-450 n m. A photokinetic model is presented for the reaction which is generally ap plicable for any two component photochemical system. The electrical power a nd distance dependence of the conversion degree and the UV intensity of the lamps was investigated. (C) 1999 Elsevier Science B.V. All rights reserved .