The results on study of light sources based on spontaneous radiation of molecules KrCl* (λ ∼ 222 nm) and XeCl* (λ ∼ 308 nm) excited by a glow discharge are presented. It is demonstrated that additions of light inert gases (He and Ne) lead to increase in emission of radiation power and efficiency in mixtures Kr(Xe)-Cl2. A high-power cylindrical multi-section excilamp was built and energy, time, and spectrum characteristics have been studied. Average output power obtained in the UV spectral range were 1,9 kW at λ ∼ 222 nm and 1,1 kW at λ ∼ 308 nm with efficiencies with respect to the excitation power of up to 14%.