Pulsed lasing at the atomic barium wavelength of 1. 13 and 1. 5 mu in a 25-mm diameter, 85-cm long discharge tube is considered. The input power reached 2. 5 kW for pump-pulse repetition frequencies of 8 and 13. 3 kHz. The average laser output power is investigated as a function of the buffer gas pressure and the input power. The spectral and temporal characteristics are studied. A maximum average laser output power of 12. 5 W is obtained at an efficiency of 0. 5%; the maximum efficiency achieved was 0. 72%.