Study of velvet cathode emitting intense E-beam

Summary form only given. In this article, we discuss the emitting mechanisms of a velvet cathode (VC) emitting an intense e-beam on basis of conclusions of three sets of experiments, and give some principles for selecting velvet to get higher a brightness e-beam. In the experiment, Marx is used as the energy equipment, a 300 kV, 50 ns pulse-width (FWHM) voltage pulse of negative polarity is put through the parallel board water-media pulse-formative-line. The diode is a parallel board model. The diameter of the cathode is 90 mm. The emitting surface is an inlayed velvet cathode of 50 mm-diameter, the velvet patch is glued onto a copper base with silver glue to make the standard cathode. The A-K gap is 13 mm. The anode is a 100 mm-diameter copper board, and there are 9 symmetrically cross-distributing 1.2 mm-diameter holes in it. So, we could simultaneously measure the beam current and the emittance at the anode plane with using the anode as an electron beam collector and pepper-board.