High current plasma electron emitter

摘要

Summary form only given, as follows. A high current plasmaelectron emitter based on a miniature plasma source has been developed.The source is characterized by a high electron emission current densityand emission current, small size, and low impurity content. The emittingplasma is created by a pulsed high current gas discharge. The source isbiased negatively to extract electrons. Electron currents of the orderof 1 kA at a bias voltage of about 100 V are obtained. The source has asimple design and has proven to be very reliable in operation. Extensivestudies of the effect of the source geometry and materials have beenconducted. The gas feed through, power dissipation, and impurity contentwere measured. A high emission current, small size (3-4 cm in diameter),and low impurity generation make the source attractive for a variety offusion and technological applications. Injectors with 1 kA electronemission current and a pulse duration of 10 ms will be used for a 20 kAelectrostatic current injection experiment in the Madison SymmetricTorus (MST) reversed-field pinch