Abstract
The currents of 5-ns pulsed high-current electron beams produced in a planar vacuum diode with explosive-emission cathodes made of various materials with no external magnetic field at an average electric field strength in the gap of about 300 kV/cm have been measured and time-integrated observation of the optical luminescence of the cathode surface have been performed. Cathodes with a ceramic bushing and spring metal contacts, with ceramic plates set in a magnetic iron matrix, with blades made of stamped exfoliated graphite (Graflex), with blades made of foil fiberglass plastic, and a composite cathode made of crystalline boron and copper powders were tested. The current carried by one emission center has been estimated to range between 5 and 20 A for various cathodes. For the metal-dielectric cathode, the velocity of expansion of the cathode plasma over the ceramic surface has been estimated as 2·107 cm/s. The lifetimes of the cathodes at a pulse repetition rate of 50 Hz have been investigated.
Original language | English |
---|---|
Pages (from-to) | 772-780 |
Number of pages | 9 |
Journal | Russian Physics Journal |
Volume | 55 |
Issue number | 7 |
DOIs | |
Publication status | Published - 1 Dec 2012 |
Keywords
- cathode plasma
- composite cathode
- explosive emission
- high-current nanosecond electron beam
- metal-ceramic cathode
- Vacuum diode
ASJC Scopus subject areas
- Physics and Astronomy(all)