Large Area Thermionic Cathode and Its Prilimiary Experimental Results

A 2MeV thermionic cathode test stand was established to meet the requirement of the large area thermionic cathode system. A 100mm in diameter type ``B''thermionic dispenser cathode was developed. A 1000A emission current was produced at the voltage of the diode about 1.8MV, the pulse width about 90ns(FWHM), and the cathode temperature about 1350℃. The emission current density is 12A/cm2. The results indicate that a large area thermionic cathode which produces high quality and high current electron beams is visible. The results also indicate that the ability of cathode emission relies on the diode-vacuum and cathode-temperature.