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Herniter M.E. Getty W.D. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(6):992-1001
A Pierce-type electron gun using a planar 1.9-cm-diameter lanthanum hexaboride cathode is being studied as a robust thermionic emitter at high cathode-current densities. The gun has been operated up to voltages of 115 kV, achieving beam current densities of 30 A/cm2 . The electron gun operated dependably up to 90 kV, achieving temperature-limited currents of 50 A. Due to the high fields at the tip of the Pierce-focusing electrode, the gun would usually arc at voltages >90 kV. Ten shots were obtained at a gun voltage of 115 kV, achieving transmitted currents up to 89 A, transmitted beam power up to 10.2 MW, and transmitted power densities up to 3.4 MW/cm2 相似文献
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Lipscomb G.A. Herniter M.E. Getty W.D. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1989,17(6):898-905
A pulsed-mode heating method has been developed and tested for a 1-in.-diameter cathode which reduces the average filament power by over an order of magnitude. The method allows cyclic operation with a few seconds of peak cathode temperature, which allows many microsecond-duration electron pulses to be fired at the peak cathode temperature in each cycle. For a 2-in.-diameter 0.125-in.-thick LaB6 cathode, the saving is just as great. A 1.68-mF capacitor at 6 kV can cycle the larger cathode from 494° to 1800°C and back in 120 s. The energy requirement is 30.2 kJ, which is an average power of 252 W. This is still a saving of over an order of magnitude from the case of steady heating. The same cathode thickness as in the 1-in. case is assumed in this prediction 相似文献
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