Generation of high-current large-cross-section electron beams in a vacuum diode with rod current returns

• Published in: Instruments and experimental techniques (New York) 2015-07, Vol.58 (4), p.525-530
• Main Authors: Abdullin, E. N., Ivanov, N. G., Losev, V. F.
• Format: Article
• Language: English
• Subjects: Electrical Engineering; General Experimental Techniques; Measurement Science and Instrumentation; Physical Chemistry; Physics; Physics and Astronomy
• ISSN: 0020-4412; 1608-3180
• DOI: 10.1134/S0020441215030148

The results of experiments on obtaining high-current radially converging extended electron beams in a vacuum diode of an electron accelerator, which is intended for excitation of a gas laser, are presented. To reduce the magnetic field in the diode and its influence on the beam formation, in addition to magnetically shielding plates that sectionalize the diode into two magnetically shielded diodes, small-diameter rod current returns were used. Cathodes with wide concave emitting units, which provided a high degree of filling the output windows with the electron beam, were used. The rods are installed in holes between the emitting units and connect the cell ribs to the vacuum-chamber wall. A significant decrease in the angles of electron entry into the foil was observed. It is shown experimentally that mounting the current returns results in a decrease in the magnetic field in the diode, while breakdowns and a decrease in the electron-beam current-pulse duration are absent. At a diode voltage of 550 kV, electron beams with a current of 240 kA, a beam energy in the diode of 20 kJ, and an extracted-beam energy transported through the foil of 6.5 kJ were obtained. The possibility of increasing the electron-beam energy, which is transferred from the diode to the gas-filled cell, by a factor of at least 1.2 was demonstrated.