Fig. 1. Acceleration voltage waveforms of induction cavity under normal operation and flashover happened

Fig. 2. Waveforms of diode voltage and electron beams with 5 cm velvet cathode and 7 cm cathode

Fig. 3. Waveform of electron beam at injector exit and accelerator exit

Fig. 4. Waveforms of diode voltage，electron beam at injector downstream and at 20 m downstream

Fig. 5. Acceleration gap of an induction cavity