Comparison of visible spectra of the accelerating gap of a pulsed electron accelerator in a vacuum diode with cathodes made of different materials

A possibility of monitoring of the operating mode of the plasma emitter of electrons of a pulsed accelerator (300 keV, 0.5 μs) is considered on the basis of the analysis of the visible radiation spectrum in the region of the accelerating gap. The spectrum was recorded using the optical system of a complex diagnostic device for controlling the parameters of the vacuum diode of the accelerator and spectrometer, the optical probe of which is mounted opposite the accelerating gap and is protected from the direct action of an electron beam. Characteristic visible spectra were recorded in the region of the accelerating gap for cathodes made of common structural materials (copper, graphite, and stainless steel), which makes it possible to distinguish between the electron beam generation mode and vacuum gap short-circuiting mode.