Efficient room-temperature operation of a fast-axial-flow rf-discharge-excited CO laser is described. A steady-state laser output of 268 W has been obtained with a CO/N(2)/He/Xe/O(2) mixture from a 19-mm-diameter, 300-mm-long discharge. The corresponding electrical conversion efficiency and the specific laser output are as high as 13.5% and 3.15 W/cm(3), respectively. The role of Xe in the mixtures is discussed. The specific laser output achieved is comparable with those of the high-power industrial CO(2) lasers in which a similar excitation scheme is applied.

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The development of Superconducting Electro-Magnetic Propulsion Ship has been going on, featuring a new propulsion concept that has never been actually applied to any ship before. The propulsion of the ship is performed by the thrust force with the use of superconducting electo magnetic thruster instead of the conventional system.Initiated by Ship & Ocean Foundation (old name: Japan Foundation for Shipbuilding Advancement) in 1985, the research and development have been continued on superconducting magnet, electrode, liquil helium refrigerator, hull form, etc. The study is now coming to the final stage, followed by the sea trial expected in next year.In this paper, the result of the study and design concept of the said experimental ship is focussed on the propulsion system as to the feature of the propulsion plant.