Fast measurements of electron emission current and X-ray intensity during pulsed vacuum breakdown

Breakdown experiments were performed for a point-plane gap in a technical vacuum by applying overshooting 1/50- mu s impulse voltage. The electron emission current and X-ray intensity during breakdown development were measured with a high-bandwidth measuring system. These measurements were synchronized with the ultrafast streak photography of breakdown development. The streak photographs showed oscillations in cathode luminosity which had a constant frequency of 200 MHz, while the waveforms of electron emission current and X-ray intensity showed no oscillations. The results show that models that attribute oscillations of cathode luminosity to oscillations in the electron emission current are invalid.<
>