| 摘要 |
Efficiency of non-equilibrium magnetohydrodynamic generators is markedly increased by provision of thermionically emitting cathodes. Cesium in concentrations 0.1 to 0.3 percent improves plasma conductivity, and when deposited on hot tungsten vastly improves thermionic emission but only in absolute concentrations which, near atmospheric pressure, greatly exceed 0.1 to 0.3 percent. Cesium is applied topically in sufficient concentrations to tungsten surface either from dispenser arrangement in which cesium passes through tungsten cathode face, or through apertures in channel wall adjacent to tungsten cathode face; amounts used are such that, after passage into main gas stream and mixture therewith, cesium concentration is still within permissible limits for improving plasma conductivity. Alternatively, generator is operated at high gas pressure (e.g., 5 atmospheres) so that the requisite absolute cesium concentration for thermionic emission is only the permissible 0.1 to 0.3 percent of the concentration of the pressurized plasma. The Invention herein described was made in the course of or under a contract or subcontract thereunder, (or grant) with the Department of the Navy.
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