Test of a single stage 1-MV prototype induction voltage cavity

A single stage 1-MV prototype induction voltage cavity has been tested detailedly. Low-voltage principle experiments with injection currents of several kiloampere, and high-voltage experiments with feed pulses up to 800 kV/150 kA have been conducted. The major objective of the principle experiments is to measure the feed current symmetry. With the cavity fed by a single current, azimuthal distributions of feed currents under several typical azimuthal line configurations are measured. Meanwhile, the influence of the current asymmetry on cavity equivalent inductance is analyzed. With the cavity fed by double currents, the effects of asynchronous feed currents on current symmetry and current addition efficiency are investigated experimentally. When the cavity is single-point driven by high-power pulses, the insulator stack made of three different dielectrics is tested. The results show that the final flashover voltage of the two newly developed materials is slightly higher than that of the common PMMA.