Experimental studies of long-lifetime cold cathodes for high-powermicrowave oscillators |
| |
Authors: | Gunin AV Landl VF Korovin SD Mesyats GA Pegel IV Rostov VV |
| |
Institution: | Inst. of High-Current Electron., Acad. of Sci., Tomsk; |
| |
Abstract: | Operation of explosive-emission cold cathodes made from various materials was studied at a large number of pulses at current densities of ~1.04 A/cm2. The cathode voltage and the beam current were ~500 kV and 5 kA, respectively, with a pulsewidth of ~20 ns. At a small number of pulses (⩽103), cathodes of like geometry (even made from different materials) demonstrated similar emission properties. For most of the materials tested, with a large number of pulses (⩾103), the current risetime increased to the fullwidth of the voltage pulse and the maximum current of the vacuum diode decreased. When using a graphite cathode, the maximum current remained invariant until 108 pulses. Mass losses were measured for a series of cathode materials. The results obtained offered the possibility to realize long-lived operation of an X-band relativistic backward-wave oscillator with an almost invariant output power of 350-400 MW during 108 pulses at a pulse repetition rate of 100-150 p.p.s |
| |
Keywords: | |
|
|