Externally triggered gas diverters for water line protection

As the capacitive storage discharges into the inductive load, the energy is oscillating and after the peak of the load current the capacitive storage begins to charge in opposite polarity. The electrical strength of the water storage depends on the polarity of the charge voltage, and therefore, as it is charging in opposite polarity, this may result in water breakdown and damage of the water line hardware. Diverters are the devices that are used to protect water storages from the reversal voltage. They represent closing switches with some resistance connected in series with the diverter discharge gap. The diverters are located at the output of the water line, and the discharge gap has to break down close to the time the current in the load peaks. At this time the storage is bypassed by the diverters and the reflected energy is dissipated in the diverter resistors. Usually the discharge gap of the diverters locates in water and operates in self breakdown mode. This implies several problems like synchronization, and shock wave in water that may destroy the hardware. In order to avoid these problems, the diverters for SYRINX/GSI facility were designed with external electrical triggering and with the discharge gap operating in SF6 instead of water. The report presents test results of triggerable gas diverters at HCEI at charge voltage up to 1 MV, and the performance of four such diverters on SYRINX/GSI water line.