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This paper presents an experimental study on the failure mechanism of high-current gallium arsenide photoconductive semiconductor switches (GaAs PCSSs) triggered by the laser diode. We propose a Blumlein pulse forming line to test the GaAs PCSS. The result shows that the damage of GaAs PCSS almost occurs at the anode under the circumstances that either anode or cathode is illuminated, since the highest amplitude of Gunn oscillation always occurs on the anode. We speculate that the failure of high-current GaAs PCSS is attributed to the Gunn effect according to the statistics about failure factors of GaAs PCSS. We use a scanning electron microscope to semiquantitatively analyze the compositions of the erosions microball or granules, which are gallium and arsenium. The result proves our speculation. [ABSTRACT FROM AUTHOR]

A B-dot was used for measuring cathode emission current in the injector of a linear induction electron accelerator. The measured current waveforms in commissioning were different from our initial expectation. This could well be explained by that the measured current waveform was the sum of actual emission current and displacement current. The displacement current could be derived by the measured diode voltage and the calculated diode capacitance. The actual emission current waveform was then obtained by subtracting the displacement current from the measured waveform. The pure displacement current waveform was also measured by the B-dot, while there was no emission from a thermionic cathode. The calculated and measured displacement current waveforms were well consistent with each other. The B-dot’s sensitivity factor calibrated by comparing the aforementioned two waveforms was equal to our theoretical estimate within an error range. The obvious displacement current may also exist in the similar pulsed power facilities, which contain high-voltage and fast pulses. It can be processed by the same methods discussed in this paper. [ABSTRACT FROM PUBLISHER]